Tag: Hubble Space Telescope

Engineers report Hubble fix appears successfully

8:50 am

Engineers this morning announced that their attempt to switch to backup computer hardware on the Hubble Space Telescope was successful.

The switch included bringing online the backup Power Control Unit (PCU) and the backup Command Unit/Science Data Formatter (CU/SDF) on the other side of the Science Instrument and Command & Data Handling (SI C&DH) unit. The PCU distributes power to the SI C&DH components, and the CU/SDF sends and formats commands and data. In addition, other pieces of hardware onboard Hubble were switched to their alternate interfaces to connect to this backup side of the SI C&DH. Once these steps were completed, the backup payload computer on this same unit was turned on and loaded with flight software and brought up to normal operations mode.

They are now doing tests to make sure everything is working as expected, and preparing the telescope to bring it out of safe mode and resume science operations.

This is great news, but to bring everyone down to Earth, we must remember that Hubble no longer has any redundancy in this area. Should there be another similar computer failure, the telescope will then be dead in the water, with the only way to bring it back a manned or robotic mission — something we presently do not have the capacity to do — to replace these units.

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Hubble update: Engineers pinpoint issue, prepare to fix it

12:38 pm

In an update today on the status for bringing the Hubble Space Telescope back into science operations, the engineers say they think they have pinpointed the failed unit, and are ready to do the switch to a backup.

A series of multi-day tests, which included attempts to restart and reconfigure the computer and the backup computer, were not successful, but the information gathered from those activities has led the Hubble team to determine that the possible cause of the problem is in the Power Control Unit (PCU).

The PCU also resides on the SI C&DH unit. It ensures a steady voltage supply to the payload computer’s hardware. The PCU contains a power regulator that provides a constant five volts of electricity to the payload computer and its memory. A secondary protection circuit senses the voltage levels leaving the power regulator. If the voltage falls below or exceeds allowable levels, this secondary circuit tells the payload computer that it should cease operations. The team’s analysis suggests that either the voltage level from the regulator is outside of acceptable levels (thereby tripping the secondary protection circuit), or the secondary protection circuit has degraded over time and is stuck in this inhibit state.

Because no ground commands were able to reset the PCU, the Hubble team will be switching over to the backup side of the SI C&DH unit that contains the backup PCU. All testing of procedures for the switch and associated reviews have been completed, and NASA management has given approval to proceed. The switch will begin Thursday, July 15, and, if successful, it will take several days to completely return the observatory to normal science operations.

Engineers did a similar switch in 2008, so they are very confident it will work this time also. However, once done, the telescope will no longer have backups for any of these computer modules. The next failure in any of them will shut the telescope down, for good.

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Engineers successful complete simulation of Hubble repair

12:30 pm

Though the details released are sparse, engineers working to get the Hubble Space Telescope back in operation since it shut down due to a computer problem in mid-June report today that they have successfully completed a simulation of the procedures they need to do to fix the problem.

This is their entire report:

[The engineers] successfully completed a test of procedures that would be used to switch to backup hardware on Hubble in response to the payload computer problem. This switch could occur next week after further preparations and reviews.

Apparently, because the switch to backup hardware requires switching more than one unit, the sequence is important and following it correctly is critical. It appears they have now determined the correct sequence and will attempt it on Hubble next week.

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Hubble update: Engineers narrow possible failed hardware to one of two units

5:09 pm

Engineers working to pinpoint the cause of the computer hardware issue that has placed the Hubble Space Telescope in safe mode since June 13th have now narrowed the possible failed hardware to one of two units.

The source of the computer problem lies in the Science Instrument Command and Data Handling (SI C&DH) unit, where the payload computer resides. A few hardware pieces on the SI C&DH could be the culprit(s).

The team is currently scrutinizing the Command Unit/Science Data Formatter (CU/SDF), which sends and formats commands and data. They are also looking at a power regulator within the Power Control Unit, which is designed to ensure a steady voltage supply to the payload computer’s hardware. If one of these systems is determined to be the likely cause, the team must complete a more complicated operations procedure to switch to the backup units. This procedure would be more complex and riskier than those the team executed last week, which involved switching to the backup payload computer hardware and memory modules. To switch to the backup CU/SDF or power regulator, several other hardware boxes on the spacecraft must also be switched due to the way they are connected to the SI C&DH unit.

Over the next week or so, the team will review and update all of the operations procedures, commands and other related items necessary to perform the switch to backup hardware. They will then test their execution against a high-fidelity simulator.

The team performed a similar switch in 2008, which allowed Hubble to continue normal science operations after a CU/SDF module failed.

That such a switch was done successfully in the past is a very hopeful sign. However, it sounds as though they are not 100% sure they have pinpointed the actual issue, which means that this switch still might not fix the problem.

We can only wait and hope. And even if the fix works, Hubble will no longer have working backup units for these pieces of hardware. Should any of the backup that are now being activated fail, the telescope will fail, and this time it won’t be fixable with the equipment on board.

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Hubble update: Still no solution

2:02 pm

An update today from the engineers trouble-shooting the problem on the Hubble Space Telescope that put it into safe mode on June 13 continue to show the problem is complex, and has not yet been traced to its source.

Additional tests performed on June 23 and 24 included turning on the backup computer for the first time in space. The tests showed that numerous combinations of [a number of] hardware pieces from both the primary and backup payload computer all experienced the same error – commands to write into or read from memory were not successful.

Since it is highly unlikely that all individual hardware elements have a problem, the team is now looking at other hardware as the possible culprit, including the Command Unit/Science Data Formatter (CU/SDF), another module on the SI C&DH [the module that holds the telescope’s computers]. The CU formats and sends commands and data to specific destinations, including the science instruments. The SDF formats the science data from the science instruments for transmission to the ground. The team is also looking at the power regulator to see if possibly the voltages being supplied to hardware are not what they should be. A power regulator ensures a steady constant voltage supply. If the voltage is out of limits, it could cause the problems observed.

They remain hopeful they can find the problem and fix it, though the longer it takes the more worrisome it becomes.

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Update on attempts to bring Hubble back to life

4:26 pm

Engineers have released an update on their attempts to bring Hubble out of safe mode that are indicating that they are honing in on the cause of the problem.

After performing tests on several of the computer’s memory modules, the results indicate that a different piece of computer hardware may have caused the problem, with the memory errors being only a symptom. The operations team is investigating whether the Standard Interface (STINT) hardware, which bridges communications between the computer’s Central Processing Module (CPM) and other components, or the CPM itself is responsible for the issue. The team is currently designing tests that will be run in the next few days to attempt to further isolate the problem and identify a potential solution.

This step is important for determining what hardware is still working properly for future reference. If the problem with the payload computer can’t be fixed, the operations team will be prepared to switch to the STINT and CPM hardware onboard the backup payload computer. The team has conducted ground tests and operations procedure reviews to verify all the commanding required to perform that switch on the spacecraft.

It appears that no matter what solution they arrive at, they will still require several days to test the solution to make sure it works. This update however is very hopeful, as it does appear they are locating the cause and have avenues for fixing it.

Hubble went into safe mode on June 13, which means it has now been out of operation for more than ten days.

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Hubble remains out of commission, with no repair date in sight

9:32 am

According to a statement to Space.com provided by the engineers trying to fix the Hubble Space Telescope, “there is no definitive timeline for bringing the computer back online.”

The Hubble operations team is working to solve the payload computer issue onboard the Hubble Space Telescope. The team is working to collect all the data available to them to isolate the problem and determine the best path forward for bringing the computer back to operations. At this time, there is no definitive timeline for bringing the computer back online. However, the team has multiple options available to them and are working to find the best solution to return the telescope to science operations as soon as possible.

…Assuming that this problem is corrected via one of the many options available to the operations team, Hubble is expected to continue yielding amazing discoveries into the late 2020s or beyond,” the operations team at NASA’s Goddard Space Flight Center in Maryland told Space.com in an email. However, “there is no definitive timeline yet as to when this will be completed, tested and brought back to operational status,

I gather from this that they do have options to might fix the problem, but they have also found the problem to be more complex than expected.

While I honestly am confident these engineers can bring the telescope back to life, we must all be prepared for the strong possibility that this might be the moment when such a repair is impossible. If so, our vision of the heavens will once again be blinded by the poor vision available to us from inside the Earth’s atmosphere. And that vision will not be cleared in the foreseeable future by an American or western optical space telescope, as none are being designed, no less built.

The Chinese however are building one, for their purposes, which will be better than Hubble and is set to launch within the next few years to fly in formation with their new space station, close by so that astronauts can do repairs if necessary.

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First attempts to fix Hubble fail

9:43 am

An attempt to switch the Hubble Space Telescope to a different backup computer module in order to bypass a broken unit failed last week, leaving the telescope in safe mode.

A payload computer on Hubble stopped working June 13, the agency said in a June 16 statement. Engineers speculated that the computer, used to manage operations of Hubble’s science instruments, malfunctioned because of a degrading memory module, putting the instruments into a safe mode.

The agency said at the time that it would switch of a backup memory module that day and, after about a day of testing, restart the instruments and resume science observations.

However, in a June 18 statement, NASA said those efforts to switch to a backup memory module failed because “the command to initiate the backup module failed to complete.” An attempt to restore the computer with both the original memory module and the backup unit also failed.

While the engineers at the Space Telescope Science Institute, that operates Hubble, have expressed confidence they can overcome these issues, the failures this week are truly troublesome. We may truly be facing the end of the telescope,

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Hubble in safe mode due to computer problem

1:47 pm

A computer failure on June 13th put the Hubble Space Telescope in safe mode, with engineers hoping to have the problem resolved and the telescope back in operation by tomorrow.

NASA is working to resolve an issue with the payload computer on the Hubble Space Telescope. The computer halted on Sunday, June 13, shortly after 4 p.m. EDT. After analyzing the data, the Hubble operations team is investigating whether a degrading memory module led to the computer halt. The team is preparing to switch to one of several backup modules on Wednesday, June 16. The computer will then be allowed to run for approximately one day to verify that the problem has been solved. The team would then restart all science instruments and return the telescope to normal science operations.

The unit itself, while built in the 1980s, was only launched to Hubble in 2009 as part of the last shuttle repair mission.

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A lopsided spiral galaxy

12:54 pm

Losided spiral galaxy
Click for full image.

For a change, today’s cool image is not from Mars, but instead goes deep into space. The photo to the right, reduced to post here, was taken by the Hubble Space Telescope of the relatively nearby spiral galaxy NGC 2276, located about 120 million light years away. As the caption explains:

The magnificent spiral galaxy NGC 2276 looks a bit lopsided in this Hubble Space Telescope snapshot. A bright hub of older yellowish stars normally lies directly in the center of most spiral galaxies. But the bulge in NGC 2276 looks offset to the upper left.

In reality, a neighboring galaxy to the right of NGC 2276 (NGC 2300, not seen here) is gravitationally tugging on its disk of blue stars, pulling the stars on one side of the galaxy outward to distort the galaxy’s normal fried-egg appearance. This sort of “tug-of-war” between galaxies that pass close enough to feel each other’s gravitational pull is not uncommon in the universe. But, like snowflakes, no two close encounters look exactly alike.

The scientists also note that the bright edge along the galaxy’s north and west perimeter mark regions of intense star-formation. In those same regions astronomers six years ago identified the first medium-sized black hole ever found.

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The changing seasons of Saturn

1:58 pm

Saturn changing
Click for full image.

Images of Saturn taken by the Hubble Space Telescope since 2018 now reveal the slow seasonal changes to the gas giant’s atmosphere during its lengthy year, twenty-nine Earth years long.

The Hubble data show that from 2018 to 2020 the equator got 5 to 10 percent brighter, and the winds changed slightly. In 2018, winds measured near the equator were about 1,000 miles per hour (roughly 1,600 kilometers per hour), higher than those measured by NASA’s Cassini spacecraft during 2004-2009, when they were about 800 miles per hour (roughly 1,300 kilometers per hour). In 2019 and 2020 they decreased back to the Cassini speeds. Saturn’s winds also vary with altitude, so the change in measured speeds could possibly mean the clouds in 2018 were around 37 miles (about 60 kilometers) deeper than those measured during the Cassini mission. Further observations are needed to tell which is happening.

The photo above shows Saturn’s northern hemisphere in 2018, 2019, and 2020. Note how the darker region at the pole grows with time.

This data supplements the data obtained by Cassini when it was in orbit around Saturn, and is presently the best information we can get since the Cassini mission ended.

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Hubble’s wide field camera returns to operation

1:39 pm

Though the Hubble Space Telescope returned to science operations on March 12th after going into safe mode, its wide field camera did not.

Engineers however now report that they have successfully restored the camera to operations as well. The reason for the delayed restoration exemplifies Hubble’s aging status.

Analysis showed that voltage levels in WFC3 power supplies have slowly decreased over time as their electronics aged. The electronics experience colder temperatures when the hardware is turned off in safe mode. This factor coupled with the power the instrument components draw as they are turned back on contributed to the small voltage fluctuation that suspended WFC3 recovery operations. Further detailed analysis indicated that it would be safe to slightly reduce the low voltage limit to avoid a future suspend, and it would be safe to recover the instrument to its science state.

The instrument has now been safely recovered. Standard calibration of the instrument and other pre-observation activities will be conducted this week.

All the telescope’s equipment has been adjusted in recent years to deal with the varying ages of its instruments and its main structure. For example, this wide field camera was installed during the last shuttle serving mission in 2009, and is therefore one of Hubble’s newest components. It however is now more than a decade old, and thus needs careful handling to function properly.

Other components are far older, such as the primary motor to open and close the telescope’s “lens cap”. That failed during this safe mode, forcing engineers to switch to a back up motor to control the cap. Whether they can recover that primary motor is presently unclear, though unlikely.

Expect more such issues in the coming years.

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Hubble about to resume science operations even with new issues

9:14 am

Engineers have fixed the computer software issue that caused the Hubble Space Telescope to go into safe mode this week, and are preparing it to return to full science operations.

It appears the problem was caused by a software upgrade that caused a conflict.

More serious however was this problem, which could have damaged the telescope beyond repair had it had been randomly pointed at the Sun during safe mode.

In entering safe mode on Sunday, however, the team discovered that the aperture door located at the top of the telescope failed to automatically close. This door is a safeguard designed to keep the Sun’s damaging light and heat out of the telescope’s interior, protecting its sensitive instruments and their surroundings. It serves as a safety net if Hubble accidently points in the direction of the Sun due to an error or hardware problem.

…The team has looked at spacecraft engineering data, run various tests, and verified that the door did indeed remain open despite the commands and power being sent to close it. Additional attempts to move the door by sending commands from the ground to its primary motor also failed to make the door move. However, the same commands sent from the ground to its backup motor did indicate movement, and that motor is now set as the primary motor. The team is looking at options to further reduce any associated risk.

It appears the primary motor that moves the door has failed. Fortunately there is a backup motor, but this is just one more item where the telescope has lost redundancy. We are very lucky that during safe mode the telescope didn’t end up pointing at the Sun, even for a very short time, for that would have ended Hubble’s operation for good. I suspect the safe mode software includes protections against that occurrence, but the possibility nonetheless existed.

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Hubble goes into safe mode

3:19 pm

Due to a software issue, the Hubble Space Telescope shifted into safe mode early yesterday and stopped doing its programmed science observations.

The engineers seem confident all will eventually be well, but we must also remember the telescope’s infrastructure (not its instruments) was built in the early 1980s and has been in space since 1990. That makes many parts of this telescope 40 years old. We are increasingly faced with the possibility of a fatal fault occurring that shuts it down for good, with no way at the present time to reach it and fix it, and with the only comparable optical space telescope in the works one being built by China to fly in formation with its space station.

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Colliding galaxies!

2:19 pm

Colliding galaxies!
Click here and here to see full images.

Cool images from Hubble! The two photos to the right, cropped and reduced to post here, shows two different galaxies undergoing a collision with another galaxy. Both images are from of a montage of six galaxy merger images from the Hubble Space Telescope, released yesterday.

To celebrate a new year, the NASA/ESA Hubble Space Telescope has published a montage of six beautiful galaxy mergers. Each of these merging systems was studied as part of the recent HiPEEC survey to investigate the rate of new star formation within such systems. These interactions are a key aspect of galaxy evolution and are among the most spectacular events in the lifetime of a galaxy.

It is during rare merging events that galaxies undergo dramatic changes in their appearance and in their stellar content. These systems are excellent laboratories to trace the formation of star clusters under extreme physical conditions.

The first galaxy merger to the right is dubbed NGC 6052, and is located in the constellation of Hercules about 230 million light-years away. This pair of colliding galaxies, according to the caption, “were first discovered in 1784 by William Herschel and were originally classified as a single irregular galaxy because of their odd shape. However, we now know that NGC 6052 actually consists of two galaxies that are in the process of colliding.”

The second image shows two galaxies, IC 694 and NGC 3690, about 700 millions after they had completed a close pass of each other. From the caption: “As a result of this interaction, the system underwent a fierce burst of star formation. In the last fifteen years or so six supernovae have popped off in the outer reaches of the galaxy, making this system a distinguished supernova factory.”

You can see all six merger images here, though to my eye these two are the most impressive.

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Dark storm on Neptune changes direction unexpectedly

8:35 am

Dark storm on Neptune
Click for full image.

Using the Hubble Space Telescope, astronomers have found that a dark storm discovered on Neptune in 2018 has been drifting across the gas giant in unexpected ways.

The storm, which is wider than the Atlantic Ocean, was born in the planet’s northern hemisphere and discovered by Hubble in 2018. Observations a year later showed that it began drifting southward toward the equator, where such storms are expected to vanish from sight. To the surprise of observers, Hubble spotted the vortex change direction by August 2020, doubling back to the north. Though Hubble has tracked similar dark spots over the past 30 years, this unpredictable atmospheric behavior is something new to see.

Equally as puzzling, the storm was not alone. Hubble spotted another, smaller dark spot in January this year that temporarily appeared near its larger cousin. It might possibly have been a piece of the giant vortex that broke off, drifted away, and then disappeared in subsequent observations.

The photo to the right, cropped and reduced to post here, shows both storms. The smaller dark spot can be seen faintly to the right of the larger storm.

Since Hubble has been observing Neptune in 1993 it has seen four such storms, all of which have faded away after about two Earth years. What causes the storms as well as their motions in Neptune’s atmosphere remains unknown, and any theories posited (such as those noted at the link) are highly unreliable, considering the paucity of data we have about Neptune’s atmosphere and the meteorology of such gas giants.

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Hubble captures 20-year fading of planetary nebula

9:10 am

The fading of the Stingray Nebula
Click for full image.

Astronomers using the Hubble Space Telescope have now tracked the spectacular fading of the Stingray Nebula, which when it was discovered in the mid-1990s was labeled the youngest such object ever found.

Astronomers have caught a rare look at a rapidly fading shroud of gas around an aging star. Archival data from NASA’s Hubble Space Telescope reveal that the nebula Hen 3-1357, nicknamed the Stingray nebula, has faded precipitously over just the past two decades. Witnessing such a swift rate of change in a planetary nebula is exceeding rare, say researchers.

Images captured by Hubble in 2016, when compared to Hubble images taken in 1996, show a nebula that has drastically dimmed in brightness and changed shape. Bright blue fluorescent tendrils and filaments of gas toward the center of the nebula have all but disappeared, and the wavy edges that earned this nebula its aquatic-themed name are virtually gone. The young nebula no longer pops against the black velvet background of the vast universe.

Astronomers have found that the central star had been heating precipitiously in the late 20th century, from 40K to 108K degrees Fahrenheit. Since then it has begun to cool. They think that flash of heat, caused by what they think was short period of helium fusion, caused the planetary nebula to brighten, and now fade.

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Hubble sees too much infrared energy from gamma ray burst

9:09 am

The uncertainty of science: During a short gamma ray burst (GRB) that was observed in a distant galaxy on May, astronomers were baffled when measurements from the Hubble Space Telescope detected ten times more near infrared energy that they predict from this type of GRB.

GRBs fall into two classes. First there are the long bursts, which are thought to form from the collapse of a massive star into a black hole, resulting in a powerful supernova and GRB. Second there are the short bursts, which scientists think occur when two neutron stars merge.

The problem with this GRB is that though it was short and somewhat similar to other short GRBs across most wavelengths, in the near infrared Hubble detected far too much energy.

“These observations do not fit traditional explanations for short gamma-ray bursts,” said study leader Wen-fai Fong of Northwestern University in Evanston, Illinois.

…Fong and her team have discussed several possibilities to explain the unusual brightness that Hubble saw. While most short gamma-ray bursts probably result in a black hole, the two neutron stars that merged in this case may have combined to form a magnetar, a supermassive neutron star with a very powerful magnetic field. “You basically have these magnetic field lines that are anchored to the star that are whipping around at about a thousand times a second, and this produces a magnetized wind,” explained Laskar. “These spinning field lines extract the rotational energy of the neutron star formed in the merger, and deposit that energy into the ejecta from the blast, causing the material to glow even brighter.”

What is intriguing about their theory is that this merger of two neutron stars simply resulted in a larger neutron star, not a black hole. This new neutron star was also a magnetar and pulsar, but unlike a black hole, it was a still-visible physical object. And yet its creation in this GRB produced more energy.

When GRBs were first discovered, I was always puzzled why so many astronomers seemed to insist there must be a single explanation for them. With time, when two classes of GRBs were discovered, this assumption was then replaced with the equally puzzling insistence that only two types of events explained them.

It seemed to me that that such explosions had too many potential variables, and could easily have a wide range of causes, though all related to the destruction or merger of massive stars. As the data continues to accumulate this now appears increasingly the case.

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Hubble creates time lapse movie of fading supernova

10:42 am

Using the Hubble Space Telescope, astronomers have created a time lapse movie showing the fading of a supernova in a nearby galaxy over a year.

The supernova is captured by Hubble in exquisite detail within this galaxy in the left portion of the image. It appears as a very bright star located on the outer edge of one of its beautiful swirling spiral arms. This new and unique time-lapse of Hubble images created by the ESA/Hubble team shows the once bright supernova initially outshining the brightest stars in the galaxy, before fading into obscurity during the year of observations. This time-lapse consists of observations taken over the course of one year, from February 2018 to February 2019.

The video of that time lapse is embedded below the fold.

The galaxy itself is located 70 million light years away. That the supernova of this single star initially outshone the entire galaxy indicates the almost unimaginable power of the explosion.
» Read more

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Hubble snaps new hi-res photo of Jupiter

10:01 am

Jupiter, as seen by Hubble in 2020
Click for full image.

Astronomers have used the Hubble Space Telescope to take a new global image of Jupiter, aimed to provide an global census of the gas giant’s storm systems.

This latest image of Jupiter, taken by NASA’s Hubble Space Telescope on August 25, 2020, was captured when the planet was 406 million miles from Earth. Hubble’s sharp view is giving researchers an updated weather report on the monster planet’s turbulent atmosphere, including a remarkable new storm brewing, and a cousin of the famous Great Red Spot region gearing up to change color – again.

The moon seen to the left is Europa. Hubble takes annual images of the planets outward from Earth in order to provide scientists this global view.

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Hubble maps giant gas halo around Andromeda

11:38 am

Astronomers using the Hubble Space Telescope’s ability to observe in ultraviolet wavelengths have now mapped the giant halo of gas that surrounds the Andromeda galaxy 2.5 million light years away.

The work found that the halo appears to have both an inner and outer shell.

“We find the inner shell that extends to about a half million light-years is far more complex and dynamic,” explained study leader Nicolas Lehner of the University of Notre Dame in Indiana. “The outer shell is smoother and hotter. This difference is a likely result from the impact of supernova activity in the galaxy’s disk more directly affecting the inner halo.”

A signature of this activity is the team’s discovery of a large amount of heavy elements in the gaseous halo of Andromeda. Heavier elements are cooked up in the interiors of stars and then ejected into space—sometimes violently as a star dies. The halo is then contaminated with this material from stellar explosions.

The Andromeda galaxy, also known as M31, is a majestic spiral of perhaps as many as 1 trillion stars and comparable in size to our Milky Way. At a distance of 2.5 million light-years, it is so close to us that the galaxy appears as a cigar-shaped smudge of light high in the autumn sky. If its gaseous halo could be viewed with the naked eye, it would be about three times the width of the Big Dipper. This would easily be the biggest feature on the nighttime sky.

Though there is of course uncertainty here, this research is confirming earlier work, making its conclusions more robust.

A side note: Ultraviolet observations can only be done in space, as the atmosphere blocks it. Hubble I think is the only telescope in space right now with this capability. There used to be others, the most noteworthy of all being the International Ultraviolet Explorer, which functioned from 1978 to 1996 but was then decommissioned because neither NASA nor ESA were willing to fund its operation any longer.

No replacements have been launched because the budget for space astronomy has almost entirely been eaten by the overbudget and long delayed James Webb Space Telescope, with future budgets to be eaten similarly by the Roman.Space Telescope.

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Astronomers use Hubble to detect ozone on Earth

8:57 am

Using the Hubble Space Telescope, scientists have shown that it will be possible to detect ozone in the atmospheres of exoplanets, using larger telescopes while observing transits of those exoplanets across the face of their star.

What the scientists did was aim Hubble at the Moon during a lunar eclipse. Moreover, they timed the observations so that the sunlight hitting the Moon and reflecting back to Earth (and Hubble) had also traveled through the Earth’s atmosphere on its way to the Moon.

They then looked at the spectrum of that light, and were able to glean from it the spectral signal of ozone in the Earth’s atmosphere. When giant ground-based telescopes under construction now come on line in the coming decades they will have the ability to do this with transiting exoplanets.

The measurements detected the strong spectral fingerprint of ozone, a key prerequisite for the presence – and possible evolution – of life as we know it in an exo-Earth. Although some ozone signatures had been detected in previous ground-based observations during lunar eclipses, Hubble’s study represents the strongest detection of the molecule to date because it can look at the ultraviolet light, which is absorbed by our atmosphere and does not reach the ground. On Earth, photosynthesis over billions of years is responsible for our planet’s high oxygen levels and thick ozone layer. Only 600 million years ago Earth’s atmosphere had built up enough ozone to shield life from the Sun’s lethal ultraviolet radiation. That made it safe for the first land-based life to migrate out of our oceans.

“Finding ozone in the spectrum of an exo-Earth would be significant because it is a photochemical byproduct of molecular oxygen, which is a byproduct of life,” explained Allison Youngblood of the Laboratory for Atmospheric and Space Physics in Colorado, USA, lead researcher of Hubble’s observations.

Ozone does not guarantee the presence of life on an exoplanet, but combined with other detections, such as oxygen and methane, would raise the odds significantly.

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A July 4th Hubble image of Saturn

10:27 am

Saturn as seen by Hubble on July 4, 2020
Click for full image, annotated.

Cool image time! The photo to the right, cropped and reduced to post here, was taken by the Hubble Space Telescope on July 4, 2020, and shows Saturn, its rings, plus several moons, in all their glory.

The dot near the bottom center is Enceladus. The dot at center right is Mimas. If you click on the annotated full image it will show the locations of several other smaller moons much harder to see.

This new Saturn image was taken during summer in the planet’s northern hemisphere.

Hubble found a number of small atmospheric storms. These are transient features that appear to come and go with each yearly Hubble observation. The banding in the northern hemisphere remains pronounced as seen in Hubble’s 2019 observations, with several bands slightly changing color from year to year. The ringed planet’s atmosphere is mostly hydrogen and helium with traces of ammonia, methane, water vapor, and hydrocarbons that give it a yellowish-brown color.

Hubble photographed a slight reddish haze over the northern hemisphere in this color composite. This may be due to heating from increased sunlight, which could either change the atmospheric circulation or perhaps remove ices from aerosols in the atmosphere. Another theory is that the increased sunlight in the summer months is changing the amounts of photochemical haze produced.

The distance across from one end of the rings to the other is about 150,000 miles, about two thirds the distance from the Earth to the Moon.

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Midnight repost: Behind the Black

11:59 pm

In celebration of the tenth anniversary the Behind the Black, I will each evening at midnight this month repost an earlier essay or article posted on the website sometime during the past ten years. Since I have posted more than 22,000 times since I started this website in July of 2010, I have plenty of good stuff to choose from. The thirty reposts over the next month will highlight some of the best.

We begin with what is really the only Easter Egg on Behind the Black, as it has sat as a unheralded link dubbed only Behind the Black on the main page since the website’s beginning. That link takes you to the following essay, excerpted and adapted from the final afterword in the paperback edition of my book about the Hubble Space Telescope, The Universe in a Mirror.

It explains much about my goals in all that I write.
————————————
Behind the Black

At the end of the last spacewalk during this last servicing mission to Hubble, astronaut John Grunsfeld took a few moments to reflect on Hubble’s importance. This was Grunsfeld’s third spaceflight and eighth spacewalk to Hubble, and no one had been more passionate or dedicated in his effort to get all of Hubble’s repairs and upgrades completed.

“As Arthur C. Clarke says,” Grunsfeld said, “the only way of finding the limits of the possible is by going beyond them into the impossible.”

For most of human history, the range of each person’s experience was of a distant and unreachable horizon. This untouchable horizon defined “the limits of the possible.” No matter how far an individual traveled, there was always a forever receding horizon line of unknown territory tantalizingly out of reach before him.
» Read more

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Two new multi-wavelength Hubble images of planetary nebulae

11:05 am

Hubble images of the Butterfly and Jewel Bug planetary nebulae
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Cool images from Hubble! Astronomers have used the Hubble Space Telescope’s entire suite of instruments to produce spectacular new multi-wavelength images of two planetary nebulae, stars that for some reasons not yet entirely understood are surrounded by breath-taking jets and cloud-formations of all shapes and sizes.

The two images are to the right, cropped and reduced to post here.

Planetary nebulas, whose stars shed their layers over thousands of years, can turn into crazy whirligigs while puffing off shells and jets of hot gas. New images from the Hubble Space Telescope have helped researchers identify rapid changes in material blasting off stars at the centers of two nebulas — causing them to reconsider what is happening at their cores.

In the case of NGC 6302, dubbed the Butterfly Nebula, two S-shaped streams indicate its most recent ejections and may be the result of two stars interacting at the nebula’s core. In NGC 7027, a new cloverleaf pattern — with bullets of material shooting out in specific directions — may also point to the interactions of two central stars. Both nebulas are splitting themselves apart on extremely short timescales, allowing researchers to measure changes in their structures over only a few decades.

This is the first time both nebulas have been studied from near-ultraviolet to near-infrared light, a complex, multi-wavelength view only possible with Hubble.

The press release suggests that the most likely and popular explanation for the formation of planetary nebula is the interaction of two closely orbiting stars. While this might be true, it remains only one theory among many, all of which explain some of what we see and none of which explain everything. As I noted in my November 2014 cover story about planetary nebulae for Sky & Telescope:
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Hubble captures giant galaxy

2:01 pm

Giant spiral galaxy imaged by Hubble
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Cool image time! The above image, cropped and reduced to post here, was compiled from images taken by the Hubble Space Telescope in 2018 of one of the largest known spiral galaxies.

One of the most photogenic is the huge spiral galaxy UGC 2885, located 232 million light-years away in the northern constellation, Perseus. It’s a whopper even by galactic standards. The galaxy is 2.5 times wider than our Milky Way and contains 10 times as many stars, about 1 trillion. This galaxy has lived a quiescent life by not colliding with other large galaxies. It has gradually bulked up on intergalactic hydrogen to make new stars at a slow and steady pace over many billions of years. The galaxy has been nicknamed “Rubin’s galaxy,” after astronomer Vera Rubin (1928 – 2016). Rubin used the galaxy to look for invisible dark matter. The galaxy is embedded inside a vast halo of dark matter. The amount of dark matter can be estimated by measuring its gravitational influence on the galaxy’s rotation rate.

This majestic spiral galaxy might earn the nickname the “Godzilla Galaxy” because it may be the largest known in the local universe. The galaxy, UGC 2885, is 2.5 times wider than our Milky Way and contains 10 times as many stars.

But it is a “gentle giant,” say researchers, because it looks like it has been sitting quietly over billions of years, possibly sipping hydrogen from the filamentary structure of intergalactic space. This fuels modest ongoing star birth at half the rate of our Milky Way. In fact, its supermassive central black hole is a sleeping giant, too; because the galaxy does not appear to be feeding on much smaller satellite galaxies, it is starved of infalling gas.

There are mysteries here, many of which we are as yet entirely unaware of yet.

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New Hubble images of Comet 2I/Borisov

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Comet 2I/Borisov taken by Hubble prior to and at its closest approach to Sun
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Scientists today released new images taken by the Hubble Space Telescope of the interstellar object Comet 2I/Borisov. The image on the left was taken prior to the comet’s closest approach to the Sun, while the image on the right was taken during that closest approach. The vertical smeared object to the left in the earlier image is a galaxy that happened to be in the field of view. The blue color of both images is a false color to bring out details.

“Hubble gives us the best upper limit of the size of comet Borisov’s nucleus, which is the really important part of the comet,” said David Jewitt, a UCLA professor of planetary science and astronomy, whose team has captured the best and sharpest look at this first confirmed interstellar comet. “Surprisingly, our Hubble images show that its nucleus is more than 15 times smaller than earlier investigations suggested it might be. Our Hubble images show that the radius is smaller than half-a-kilometer. Knowing the size is potentially useful for beginning to estimate how common such objects may be in the solar system and our galaxy. Borisov is the first known interstellar comet, and we would like to learn how many others there are.”

The first image was taken from a distance of 203 million miles, while the second was taken from 185 million miles. Expect more images in late December, when the comet makes its closest approach to Earth at a distance of 180 million miles.

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New Hubble image of Saturn

9:30 am

Saturn taken by Hubble in 2019
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Astronomers have used the Hubble Space Telescope to snap a new high resolution image of Saturn. That image, cropped and reduced to post here, can be seen on the right.

The image was part of a new Hubble program to obtain regular images of the outer planets, begun in 2018.

[The Saturn images] reveal a planet with a turbulent, dynamic atmosphere. This year’s Hubble offering, for example, shows that a large storm visible in the 2018 Hubble image in the north polar region has vanished. Smaller storms pop into view like popcorn kernels popping in a microwave oven before disappearing just as quickly. Even the planet’s banded structure reveals subtle changes in color.

But the latest image shows plenty that hasn’t changed. The mysterious six-sided pattern, called the “hexagon,” still exists on the north pole. Caused by a high-speed jet stream, the hexagon was first discovered in 1981 by NASA’s Voyager 1 spacecraft.

As beautiful as this Hubble photograph is, I cannot help but be saddened by it. It is now the best image of Saturn we will get until 2036 at the earliest, when a NASA mission to Titan finally arrives.

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New Hubble image of Jupiter

5:39 pm

Jupiter as seen by Hubble in 2019
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The Hubble science team today released a new global image the telescope took of Jupiter on June 27, 2019. The photograph on the right is that image, reduced and cropped to post here. As noted by the press release about the Great Red Spot,

The Great Red Spot is a towering structure shaped like a wedding cake, whose upper haze layer extends more than 3 miles (5 kilometers) higher than clouds in other areas. The gigantic structure, with a diameter slightly larger than Earth’s, is a high-pressure wind system called an anticyclone that has been slowly downsizing since the 1800s. The reason for this change in size is still unknown.

A worm-shaped feature located below the Great Red Spot is a cyclone, a vortex around a low-pressure area with winds spinning in the opposite direction from the Red Spot. Researchers have observed cyclones with a wide variety of different appearances across the planet. The two white oval-shaped features are anticyclones, like small versions of the Great Red Spot.

Another interesting detail is the color of the wide band at the equator. The bright orange color may be a sign that deeper clouds are starting to clear out, emphasizing red particles in the overlying haze.

In many ways Hubble’s images of Jupiter are comparable to those taken by Juno, except that Hubble can’t zoom in as close.

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New image of Eta Carina from Hubble

7:27 pm

Eta Carina
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Using the Hubble Space Telescope, astronomers have taken a new spectacular image of the Luminous Blue Giant star Eta Carina. The image on the right is that photograph, reduced to post here.

Using Hubble’s Wide Field Camera 3 to map the ultraviolet-light glow of magnesium embedded in warm gas (shown in blue), astronomers were surprised to discover the gas in places they had not seen it before.

Scientists have long known that the outer material thrown off in the 1840s eruption has been heated by shock waves after crashing into the doomed star’s previously ejected material. In the new images, the team had expected to find light from magnesium coming from the same complicated array of filaments as seen in the glowing nitrogen (shown in red). Instead, a completely new luminous magnesium structure was found in the space between the dusty bipolar bubbles and the outer shock-heated nitrogen-rich filaments.

Eta Carina had a major eruption in the 1840s, followed by other lesser outbursts, the evidence of which is obvious in this and other earlier Hubble images. In fact, over the past twenty-five years Hubble has actually tracked the expansion of those two lobes of material being flung from the star hidden deep in the material.

Someday in the far future astronomers believe it will die as a supernova, though that is only a hypothesis at this point, based on our presently limited understanding of stellar evolution.

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