Search Results for: Hubble

Probe to visit 8 asteroids, not 7

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Scientists developing the Lucy mission to visit seven Trojan asteroids that share an orbit with Jupiter have found an eighth satellite they will also be able to visit.

This first-ever mission to the Trojans was already going to break records by visiting seven asteroids during a single mission. Now, using data from the Hubble Space Telescope (HST), the Lucy team discovered that the first Trojan target, Eurybates, has a satellite. This discovery provides an additional object for Lucy to study.

“If I had to bet that one of our destinations had a satellite, it would have been this one,” said SwRI’s Hal Levison, principal investigator of the mission. “Eurybates is considered the largest remnant of a giant collision that occurred billions of years ago. Simulations show that asteroid collisions like the one that made Eurybates and its family often produce small satellites.”

The mission is targeting a 2021 launch date.

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Hubble captures giant galaxy

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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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The importance of small telescopes to science and civilization

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The main cluster of telescopes, on Mount Lemmon
Largest cluster of telescopes on Mount Lemmon, six visible with three just out of view.

On December 11, 2019 I was kindly given a personal tour by Alan Strauss, director of the Mount Lemmon Sky Center, of the telescopes located on the mountaintops of the Santa Catalina Mountains overlooking Tucson. Strauss runs the educational outreach program for the University of Arizona astronomy department and the Steward Observatory, both of which operate the mountaintop facility.

The telescopes, numbering almost a dozen, are in two groups, two telescopes on the peak of Mount Bigelow and the rest clustered on the higher peak of Mount Lemmon. None are very gigantic by today’s standards, with their primary mirrors ranging in size from 20- to 61-inches. For comparison, the largest operating telescope in the world on the Canary Islands is 409 inches across. Hubble has a 94-inch mirror. And the new giant telescopes under design or being built have mirrors ranging from 842 inches (Giant Magellan) to 1,654 inches (European Extremely Large Telescope).

Thus, the small telescopes in the Santa Catalinas generally don’t make the news. They are considered passe and out-of-date, not capable of doing the kind of cutting edge astronomy that all the coolest astronomers hunger for.

Yet, without them, we likely would not have future astronomers. » Read more

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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 Horizons team renames “Ultima Thule” to “Arrokoth”

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The New Horizons team has renamed the Kuiper Belt object that the spacecraft flew past on January 1, 2019 from its informal nickname of “Ultima Thule” to “Arrokoth,” which means “sky” in Powhatan/Algonquian language.

This official, and very politically correct, name has apparently gotten the stamp of approval from the IAU.

In accordance with IAU naming conventions, the discovery team earned the privilege of selecting a permanent name for the celestial body. The team used this convention to associate the culture of the native peoples who lived in the region where the object was discovered; in this case, both the Hubble Space Telescope (at the Space Telescope Science Institute) and the New Horizons mission (at the Johns Hopkins Applied Physics Laboratory) are operated out of Maryland — a tie to the significance of the Chesapeake Bay region to the Powhatan people.

“We graciously accept this gift from the Powhatan people,” said Lori Glaze, director of NASA’s Planetary Science Division. “Bestowing the name Arrokoth signifies the strength and endurance of the indigenous Algonquian people of the Chesapeake region. Their heritage continues to be a guiding light for all who search for meaning and understanding of the origins of the universe and the celestial connection of humanity.” [emphasis mine]

It is a good name, especially because its pronunciation is straight-forward, unlike the nickname.

The blather from Glaze above, however, is quite disingenuous. The Algonquian people have had literally nothing to do with the modern scientific quest for “meaning and understanding of the origins of the unverse.” They were a stone-age culture, with no written language. It was western civilization that has made their present lives far better. And it was the heritage of western civilization, not “the indigenous Algonquian people” that made the New Horizons’ journey possible. Without the demand for knowledge and truth, as demanded by western civilization, we would still not know that Arrokoth even existed.

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Bennu & Ryugu: Two very old and strange asteroids

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Bennu as seen by OSIRIS-REx
Bennu’s equatorial ridge. Click for full image.

This week the science team operating the OSIRIS-REx spacecraft at the asteroid Bennu hosted a joint conference in Tucson, Arizona, with the scientists operating the Hayabusa-2 spacecraft at the asteroid Ryugu. Both gave up-to-date reports on the science so far obtained, as well as outlined upcoming events. I was fortunate enough to attend.

First an overview. Both Bennu and Ryugu are near earth asteroids, with Bennu having an orbit that might even have it hit the Earth in the last quarter of 2100s. Both are very dark, and are rubble piles. Both were thought to be of the carbonaceous chondrite family of asteroids, sometimes referred to as C-type asteroids. This family, making up about 75% of all asteroids, includes a bewildering collection of subtypes (B-types, F-types, G-types, CI, CM, CV, CH, CB, etc), all of which were initially thought to hold a lot of carbon. We now know that only a few of these categories, the CI and CM for example, are carbon rich.

Even so, we actually know very little about these types of asteroids. They are very fragile, so that any that reach the Earth’s surface are not a good selection of what exists. About 90% of the material gets destroyed in the atmosphere, with the remnant generally coming from the innermost core or more robust nodules. We therefore have a biased and limited sample.

It is therefore not surprising that the scientists are finding that neither Bennu nor Ryugu resembles anything else they have ever seen. Both have aspects that resemble certain types of carbonaceous chondrite asteroids, but neither provides a very good fit for anything.
» Read more

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New estimate for Hubble constant differs from previous and also conflicting results

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The uncertainty of science: Using microlensing effects scientists have measured a new estimate for the Hubble constant, the rate in which the universe is expanding, and have come up with a number that is different from previous results.

Using adaptive optics technology on the W.M. Keck telescopes in Hawaii, they arrived at an estimate of 76.8 kilometers per second per megaparsec. As a parsec is a bit over 30 trillion kilometers and a megaparsec is a million parsecs, that is an excruciatingly precise measurement. In 2017, the H0LICOW team published an estimate of 71.9, using the same method and data from the Hubble Space Telescope.

The new SHARP/H0LICOW estimates are comparable to that by a team led by Adam Reiss of Johns Hopkins University, 74.03, using measurements of a set of variable stars called the Cepheids. But it’s quite a lot different from estimates of the Hubble constant from an entirely different technique based on the cosmic microwave background. That method, based on the afterglow of the Big Bang, gives a Hubble constant of 67.4, assuming the standard cosmological model of the universe is correct.

An estimate by Wendy Freedman and colleagues at the University of Chicago comes close to bridging the gap, with a Hubble constant of 69.8 based on the luminosity of distant red giant stars and supernovae.

So five different teams have come up with five different numbers, ranging from 67.4 to 76.8 kilometers per second per megaparsec. Based on the present understanding of cosmology, however, the range should have been far less. By now the physicists had expected these different results to be close to the same. The differences suggest that either their theories are wrong, or their methods of measurement are incorrect.

The most likely explanation is that we presently have too little knowledge about the early universe to form any solid theories. These measurements are based on a very tiny amount of data that also require a lot of assumptions.

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Hubble snaps photo of Comet Borisov

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Comet Borisov by Hubble
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Cool image time! Using the Hubble Space Telescope astronomers have snapped the best image so far of interstellar Comet Borisov. The image to the right, reduced and cropped to post here, is that photograph.

Comet 2I/Borisov is only the second such interstellar object known to have passed through our Solar System. In 2017, the first identified interstellar visitor, an object dubbed ‘Oumuamua, swung within 38 million kilometres of the Sun before racing out of the Solar System. “Whereas ‘Oumuamua looked like a bare rock, Borisov is really active, more like a normal comet. It’s a puzzle why these two are so different,” explained David Jewitt of UCLA, leader of the Hubble team who observed the comet.

The comet was 260 million miles away when Hubble took this picture.

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New Hubble image of Saturn

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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

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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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A heavy metal exoplanet, a star with no iron

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Two strangely related astronomy stories to start the day:

The first describes a weird planet so hot that metals are gas in the atmosphere:

A scorching planet, WASP-121b orbits precariously close to a star that is even hotter than our Sun. The intense radiation heats the planet’s upper atmosphere to a blazing 4,600 degrees Fahrenheit. Apparently, the lower atmosphere is still so hot that iron and magnesium remain in gaseous form and stream to the upper atmosphere, where they escape into space on the coattails of hydrogen and helium gas.

The sizzling planet is also so close to its star that it is on the cusp of being ripped apart by the star’s intense pull. This hugging distance means that the planet is stretched into a football shape due to gravitational tidal forces.

The presence of so much heavy elements suggests this planet and star formed relatively recently in the history of the universe, after many generations of star formation made possible the creation of those elements.

The second describes a star so devoid of iron that it hints of the first stars that ever formed.

The very first stars in the Universe are thought to have consisted of only hydrogen and helium, along with traces of lithium. These elements were created in the immediate aftermath of the Big Bang, while all heavier elements have emerged from the heat and pressure of cataclysmic supernovae – titanic explosions of stars. Stars like the Sun that are rich in heavy element therefore contain material from many generations of stars exploding as supernovae.

As none of the first stars have yet been found, their properties remain hypothetical. They were long expected to have been incredibly massive, perhaps hundreds of times more massive than the Sun, and to have exploded in incredibly energetic supernovae known as hypernovae.

The confirmation of the anaemic SMSS J160540.18–144323.1, although itself not one of the first stars, adds a powerful bit of evidence.

Dr Nordlander and colleagues suggest that the star was formed after one of the first stars exploded. That exploding star is found to have been rather unimpressive, just ten times more massive than the Sun, and to have exploded only feebly (by astronomical scales) so that most of the heavy elements created in the supernova fell back into the remnant neutron star left behind.

Only a small amount of newly forged iron escaped the remnant’s gravitational pull and went on, in concert with far larger amounts of lighter elements, to form a new star – one of the very first second generation stars, that has now been discovered.

All the the science and data with both stories is highly uncertain. Both however point to the complex and hardly understood process that made us possible.

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Astronomers map exoplanet atmosphere of super-Earth

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Worlds without end: Using both the Hubble and Spitzer space telescopes, astronomers have characterized the atmosphere of an exoplanet with a mass between that of the Earth and Neptune.

Astronomers enlisted the combined multi-wavelength capabilities NASA’s Hubble snd Spitzer space telescopes to do a first-of-a-kind study of GJ 3470 b’s atmosphere. This was accomplished by measuring the absorption of starlight as the planet passed in front of its star (transit) and the loss of reflected light from the planet as it passed behind the star (eclipse). All totaled, the space telescopes observed 12 transits and 20 eclipses. The science of analyzing chemical fingerprints based on light is called “spectroscopy.”

“For the first time we have a spectroscopic signature of such a world,” said Benneke. But he is at a loss for classification: Should it be called a “super-Earth” or “sub-Neptune?” Or perhaps something else?

Fortuitously, the atmosphere of GJ 3470 b turned out to be mostly clear, with only thin hazes, enabling the scientists to probe deep into the atmosphere. “We expected an atmosphere strongly enriched in heavier elements like oxygen and carbon which are forming abundant water vapor and methane gas, similar to what we see on Neptune”, said Benneke. “Instead, we found an atmosphere that is so poor in heavy elements that its composition resembles the hydrogen/helium rich composition of the Sun.”

To me, our knowledge of exoplanets today is beginning to resemble our knowledge of the planets in the solar system c. 1950. The little data we have gives us a vague idea of what’s there, but there are so many gaps and uncertainties that no one should be confident about drawing any firm conclusions.

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New image of Eta Carina from Hubble

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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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New analysis throws wrench in formation theory of spirals in galaxies

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The uncertainty of science: A new analysis of over 6000 galaxies suggests that a long-held model for the formation of spirals in galaxies is wrong.

[Edwin] Hubble’s model soon became the authoritative method of classifying spiral galaxies, and is still used widely in astronomy textbooks to this day. His key observation was that galaxies with larger bulges tended to have more tightly wound spiral arms, lending vital support to the ‘density wave’ model of spiral arm formation.

Now though, in contradiction to Hubble’s model, the new work finds no significant correlation between the sizes of the galaxy bulges and how tightly wound the spirals are. This suggests that most spirals are not static density waves after all.

Essentially, we still have no idea why spirals form in galaxies.

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Astronomers call for regulations to stop commercial satellite constellations

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The astronomical community is now calling for new regulations to restrict the number of satellites that can be launched as part of the coming wave of new commercial constellations due to a fear these satellites will interfere with their observations.

Not surprising to me, it is the International Astronomical Union (IAU) that is taking the lead here.

The IAU statement urges satellite designers and policymakers to take a closer look at the potential impacts of satellite constellations on astronomy and how to mitigate them.

“We also urge appropriate agencies to devise a regulatory framework to mitigate or eliminate the detrimental impacts on scientific exploration as soon as practical,” the statement says. “We strongly recommend that all stakeholders in this new and largely unregulated frontier of space utilisation work collaboratively to their mutual advantage.”

When it comes to naming objects in space, the IAU likes to tell everyone else what to do. That top-down approach is now reflected in its demand that these commercial enterprises, with the potential to increase the wealth and knowledge of every human on Earth, be shut down.

The astronomy community has a solution, one that it has been avoiding since they launched Hubble in 1990, and that is to build more space-telescopes. Such telescopes would not only leap-frog the commercial constellations, it would routinely get them better results, far better than anything they get on Earth.

But no, they’d rather squelch the efforts of everyone else so they can maintain the status quo. They should be ashamed.

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New Hubble data baffles cosmologists about universe’s expansion rate

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The uncertainty of science: New and very firm data from the Hubble Space Telescope on the universe’s expansion rate conflicts with just-as-firm data obtained by Europe’s Planck astronomical probe.

According to Planck, the present universe should be expanding at a rate of 67 kilometers per second per megaparsec. According to Hubble, the actual expansion rate is 74 kilometers per second per megaparsec.

And according to the scientists involved, both data sets are reliable and trustworthy, leaving them baffled at the difference.

“This is not just two experiments disagreeing,” explained [lead researcher and Nobel laureate Adam Riess of the Space Telescope Science Institute (STScI) and Johns Hopkins University, in Baltimore, Maryland.] “We are measuring something fundamentally different. One is a measurement of how fast the universe is expanding today, as we see it. The other is a prediction based on the physics of the early universe and on measurements of how fast it ought to be expanding. If these values don’t agree, there becomes a very strong likelihood that we’re missing something in the cosmological model that connects the two eras.”

Ya think? Any cosmologist who claims we really understand what is going on, based on our present fragile and very limited knowledge, is either fooling him or herself or is trying to fool us.

I should note that there seems to be an effort, based on the press release above as well as this second one, to downplay the amount of uncertainties that exist in this cosmological work. Both releases fail to note that when scientists announced their first expansion rate estimate from Hubble’s first data back in 1995, those scientists claimed with absolute certainty that the expansion rate was 80 kilometers per second per megaparsec. At the time some scientists, led by the late Allan Sandage of the Carnegie Observatory, disputed this high number, claiming the number could be as low as 50. Some even said it could be as low as 30 kilometers. Sandage especially found himself poo-pooed by the cosmological community for disputing that the 80 number pushed by Hubble’s scientists in 1995.

In the end, the Hubble scientists in 1995 were closer to today’s Hubble number than Sandage, but his estimate was not wrong by that much more, and he was right when he said the number had to be lower. Either way, Hubble’s modern estimate of 74 for the present expansion rate is very well constrained, and is a far more trustworthy number than previous estimates.

However, do we know with any reliability what the expansion rate was billions of years ago? No. Cosmologists think it was faster, based on supernovae data, which is where the theory of dark energy comes from. It is also where Planck’s predictions come from.

That early expansion rate, however, is based on such tentative data, containing so many assumptions and such large margins of error, that no serious scientist should take it too seriously. It suggests things, but it certainly doesn’t confirm them.

This is why their faith in the numbers derived from Planck puzzles me. It is based on a “prediction,” as Riess admits in the quote above, which means it is based on a theoretical model. It is also based on that very tentative early supernovae data, which makes it very suspect to me.

The Hubble data is real data, obtained by looking at nearby stars in a very precise matter. Its margin of error is very small. It contains only a few assumptions, mostly involving our understanding of the Cepheid variable stars that Hubble observed. While skepticism is always called for, trusting this new Hubble data more is perfectly reasonable.

In the end, to really solve this conflict will require better data from the early universe. Unfortunately, that is not something that will be easy to get.

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Hubble celebrates 29 years in orbit

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Hubble's 29th anniversary image

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In celebration of the 29th anniversary of the launch of the Hubble Space Telescope, the Space Telescope Science Institute (STScI) that operates the telescope has released a new image of one of the more spectacular astronomical objects in the southern hemisphere, what astronomers have dubbed the Southern Crab Nebula. I have cropped and reduced the image slightly to post it to the right.

The nebula, officially known as Hen 2-104, is located several thousand light-years from Earth in the southern hemisphere constellation of Centaurus. It appears to have two nested hourglass-shaped structures that were sculpted by a whirling pair of stars in a binary system. The duo consists of an aging red giant star and a burned-out star, a white dwarf. The red giant is shedding its outer layers. Some of this ejected material is attracted by the gravity of the companion white dwarf.

The result is that both stars are embedded in a flat disk of gas stretching between them. This belt of material constricts the outflow of gas so that it only speeds away above and below the disk. The result is an hourglass-shaped nebula.

The bubbles of gas and dust appear brightest at the edges, giving the illusion of crab leg structures. These “legs” are likely to be the places where the outflow slams into surrounding interstellar gas and dust, or possibly material which was earlier lost by the red giant star.

The outflow may only last a few thousand years, a tiny fraction of the lifetime of the system. This means that the outer structure may be just thousands of years old, but the inner hourglass must be a more recent outflow event. The red giant will ultimately collapse to become a white dwarf. After that, the surviving pair of white dwarfs will illuminate a shell of gas called a planetary nebula.

Hubble first revealed this nebula’s shape in a photograph taken in 1999.

The telescope was initially designed for a fifteen year mission. It is about to double that, assuming its last remaining gyroscopes can hold on through next year.

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Hubble’s main camera resumes science work

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The main camera on the Hubble Space Telescope has resumed science operations after going into safe mode last week.

At 8:31 p.m. EST on Feb. 28, the Advanced Camera for Surveys aboard NASA’s Hubble Space Telescope suspended operations after an error was detected as the instrument was performing a routine boot procedure. The error indicated that software inside the camera had not loaded correctly in a small section of computer memory. The Hubble operations team ran repeated tests to reload the memory and check the entire process. No errors have been detected since the initial incident, and it appears that all circuits, computer memory and processors that are part of that boot process are now operating normally. The instrument has now been brought back to its standard operating mode for normal operations.

From the press release, it appears that they have not been able to trace why the error occurred. However, much like a typical Windows computer, after a mysterious crash and reboot now all appears well, so they have shrugged their shoulders and moved on.

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Hubble’s main camera down

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The main camera on the Hubble Space Telescope has suspended operations, and remains so as engineers troubleshoot the problem.

According to NASA, at 8:31 p.m. EST Feb. 28 (01:31 GMT March 1), 2019, the Advanced Camera for Surveys, or ACS, suspended its operations when an error was detected while the instrument was performing a routine boot procedure. “The error indicated that software inside the camera had not loaded correctly,” a statement from NASA reads. “A team of instrument system engineers, flight software experts and flight operations personnel quickly organized to download and analyze instrument diagnostic information.

They have not yet pinpointed the cause of the problem. The telescope has other cameras, however, though one of which had problems several months ago.

It is ten years since the last shuttle repair mission. That mission was expected to extend the telescope’s life for five years. Thus, the end Hubble’s life is getting closer and closer.

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IAU approves China’s proposed names for Chang’e-4 landing site

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That was fast! The International Astronomical Union (IAU) has approved all of the proposed names that China submitted for the features at or near Chang’e-4 landing site.

The IAU Working Group for Planetary System Nomenclature has approved the name Statio Tianhe for the landing site where the Chinese spacecraft Chang’e-4 touched down on 3 January this year, in the first-ever landing on the far side of the Moon. The name Tianhe originates from the ancient Chinese name for the Milky Way, which was the sky river that separated Niulang and Zhinyu in the folk tale “The Cowherd and the Weaver Girl”.

Four other names for features near the landing site have also been approved. In keeping with the theme of the above-mentioned folk tale, three small craters that form a triangle around the landing site have been named Zhinyu, Hegu, and Tianjin, which correspond to characters in the tale. They are also names of ancient Chinese constellations from the time of the Han dynasty. The fifth approved name is Mons Tai, assigned to the central peak of the crater Von Kármán, in which the landing occurred. Mons Tai is named for Mount Tai, a mountain in Shandong, China, and is about 46 km to the northwest of the Chang’e-4 landing site.

Compare this fast action with the IAU’s approval process for the names the New Horizons team picked for both Pluto and Ultima Thule. It took the IAU more than two years to approve the Pluto names, and almost three years to approve the Charon names. It is now almost two months after New Horizons’ fly-by of Ultima Thule, and the IAU has not yet approved the team’s picks for that body.

Yet it is able to get China’s picks approved in less than a month? Though it is obviously possible that there is a simple and innocent explanation for the differences here, I think this illustrates well the biases of the IAU. Its membership does not like the United States, and works to stymie our achievements if it can. This factor played a part in the Pluto/planet fiasco. It played a part in its decision to rename Hubble’s Law. And according to my sources, it was part of the background negotiations in the naming of some lunar craters last year to honor the Apollo 8 astronauts.

The bottom line remains: The IAU has continually tried to expand its naming authority, when all it was originally asked to do was to coordinate the naming of distant astronomical objects. Now it claims it has the right to approve the naming of every boulder and rock anywhere in the universe. At some point the actual explorers are going to have to tell this organization to go jump in a lake.

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New Hubble images of Uranus and Neptune

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Uranus (top) and Neptune

The Hubble Space Telescope’s new annual images of Uranus (top) and Neptune (bottom) has revealed new atmospheric features for both, a giant north pole cloud cap on Uranus and a new dark storm developing on Neptune.

For Neptune:

The new Hubble view of Neptune shows the dark storm, seen at top center. Appearing during the planet’s southern summer, the feature is the fourth and latest mysterious dark vortex captured by Hubble since 1993. Two other dark storms were discovered by the Voyager 2 spacecraft in 1989 as it flew by the remote planet. Since then, only Hubble has had the sensitivity in blue light to track these elusive features, which have appeared and faded quickly. A study led by University of California, Berkeley, undergraduate student Andrew Hsu estimated that the dark spots appear every four to six years at different latitudes and disappear after about two years.

Hubble uncovered the latest storm in September 2018 in Neptune’s northern hemisphere. The feature is roughly 6,800 miles across.

For Uranus:

The snapshot of Uranus, like the image of Neptune, reveals a dominant feature: a vast bright cloud cap across the north pole.

Scientists believe this feature is a result of Uranus’ unique rotation. Unlike every other planet in the solar system, Uranus is tipped over almost onto its side. Because of this extreme tilt, during the planet’s summer the Sun shines almost directly onto the north pole and never sets. Uranus is now approaching the middle of its summer season, and the polar-cap region is becoming more prominent. This polar hood may have formed by seasonal changes in atmospheric flow.

The images are part of an annual program that monitors both planets with images every year when the Earth is best placed to view them. This allows scientists to track atmospheric changes over time.

The sharpness of both images matches that of previous Hubble images, so these photographs do not show any decline in the telescope’s image capability. However, when they lose that next gyroscope and shift to one gyroscope mode, I believe it will be very difficult to get images even this sharp of the outer planets. In fact, I suspect this monitoring program will likely have to end, or will be badly crippled.

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The unfinished search for the Hubble constant

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The uncertainty of science: Scientists continue to struggle in their still unfinished search for determining the precise expansion rate for the universe, dubbed the Hubble constant in honor of Edwin Hubble, who discovered that expansion.

The problem is, the values obtained from [two different] methods do not agree—a discrepancy cosmologists call “tension.” Calculations from redshift place the figure at about 73 (in units of kilometers per second per megaparsec); the CMB estimates are closer to 68. Most researchers first thought this divergence could be due to errors in measurements (known among astrophysicists as “systematics”). But despite years of investigation, scientists can find no source of error large enough to explain the gap.

I am especially amused by these numbers. Back in 1995 NASA had a big touted press conference to announce that new data from the Hubble Space Telescope had finally determined the exact number for the Hubble constant, 80 (using the standard above). The press went hog wild over this now “certain” conclusion, even though other astronomers disputed it, and offered lower numbers ranging from 30 to 65. Astronomer Allan Sandage of the Carnegie Observatories was especially critical of NASA’s certainty, and was dully ignored by most of the press.

In writing my own article about this result, I was especially struck during my phone interview with Wendy Friedman, the lead scientist for Hubble’s results, by her own certainty. When I noted that her data was very slim, the measurements of only a few stars from one galaxy, she poo-pooed this point. Her result had settled the question!

I didn’t buy her certainty then, and in my article, for The Sciences and entitled most appropriately “The Hubble Inconstant”, made it a point to note Sandage’s doubts. In the end it turns out that Sandage’s proposed number then of between 53 and 65 was a better prediction.

Still, the science for the final number remains unsettled, with two methods coming up with numbers that are a little less than a ten percent different, and no clear explanation for that difference. Isn’t science wonderful?

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Maxar cancels its DARPA satellite servicing mission

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Capitalsm in space: Maxar today announced it is canceling its DARPA mission to develop and fly a robotic mission aimed at servicing geosynchronous satellites.

Maxar Technologies’ Space Systems Loral division terminated an agreement to build DARPA’s Robotic Servicing of Geosynchronous Satellites spacecraft Jan. 30, leading to a potential recompete of the program. Maxar said it also canceled a contract with Space Infrastructure Services, a company it created that would have commercialized the RSGS servicer after a DARPA demonstration, starting with an in-orbit refueling mission for fleet operator SES. Both were awarded in 2017.

…The cancellations come amid an ongoing divestment of SSL’s geostationary satellite manufacturing business, which has weighed down Maxar’s financial performance due to a protracted slump in commercial orders.

More background information can be found here.

It seems that the industry’s increasing shift from a few large geosynchronous satellites to small smallsats in low Earth orbit is the real cause of this decision. Maxar has realized that there won’t be that many satellites in the future to service, since the smallsat design doesn’t require it. Smallsats aren’t designed for long life. Instead, you send them them up in large numbers, frequently. Their small size and the arrival of smallsat rockets to do this makes this model far cheaper than launching expensive big geosynchronous satellites that are expected to last ten to fifteen years and would be worth repairing.

Thus, the business model for commercial robotic servicing has apparently vanished, from Maxar’s perspective. Other servicing projects however continue. From the second link:

Northrop Grumman said it plans to launch its first Mission Extension Vehicle to dock with Intelsat-901 and take over orbital station-keeping duties, extending the satellite’s service life by several more years.

Another up and coming player, Effective Space, is developing a satellite servicing vehicle called Space Drone, to provide satellite life extension services.

And SSL [a Maxar subdivision] is under contract to NASA to build the Restore-L satellite servicing spacecraft, slated to launch in 2020. Restore-L will be owned by NASA, however, and will operate in low Earth orbit, not the geosynchronous arc as was the plan for RSGS.

The last mission is intriguing because it could lay the groundwork for a robotic servicing mission to Hubble. It is being led by the same NASA division that ran all of the shuttle servicing missions to Hubble, and is using many of the engineering designs that division proposed when it was trying to sell a Hubble robot servicing mission back in 2004.

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Fix pinpointed for Hubble main camera

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Engineers have identified the issue that put the main camera of the Hubble Space Telescope into safe mode last week, and expect to have the camera back in operation in two or three days.

Hubble’s Wide Field Camera 3 (WFC3) took itself offline last week as a safety precaution, after onboard software noticed anomalous voltage readings within the instrument. But Hubble team members have now determined that voltage levels actually remained within the normal range, ascribing the glitch to a telemetry issue rather than a power-supply problem.

The mission team reset the relevant telemetry circuits, gathered some more engineering data and then brought the WFC3 back to an operational state. “All values were normal. Additional calibration and tests will be run over the next 48 to 72 hours to ensure that the instrument is operating properly,” NASA officials wrote in a Hubble update Tuesday (Jan. 15).

None of this changes the reality that it is almost a decade since the last shuttle repair mission, and Hubble is facing a long slow decline leading to its eventual loss, with no replacement planned by anyone.

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Hubble’s main camera in safe mode

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The coming dark age: The Wide Field Camera on the Hubble Space Telescope has experienced “an anomaly” that has forced its shut down.

The announcement is a mere one paragraph long, and provides no further information.

This camera was installed on the space telescope during the last shuttle mission in 2009. It is now almost a decade since that mission, which was expected to extend Hubble’s life for at least five years. It is therefore not surprising that things are beginning to fail. In October they had a serious gyroscope problem when a gyroscope failed and they had problems getting their last back-up gyroscope to work. They got it working, but this has left us with a telescope with no gyroscope backups. With the next failure they will have to shift to one gyroscope mode, meaning sharp images will no longer be possible. Now the main camera has shut down.

Unfortunately, it appears that we are reaching the end of Hubble’s life span. The sad thing is that this shouldn’t be necessary. It can be repaired, but this would require a robot mission, something that would have been very difficult a decade ago but is quite doable at a reasonable cost today. No such mission is being considered however.

Even worse, the bad planning that is routine for our modern intellectual class has left us with no replacement, for the foreseeable future. In the late 1990s the astronomy community chose this path, deciding to replace Hubble with an infrared space telescope, the James Webb Space Telescope. They and NASA also decided to push the limits of engineering with Webb, resulting in a project that is about a decade behind schedule with a budget that has ballooned from $1 billion to $9 billion. Meanwhile, there has been no money for any other major space telescopes. And the one the astronomy community proposed in 2011, WFIRST, is already over budget and behind schedule, in its design phase.

The astronomy community has also decided in the past two decades that it could replace Hubble with giant ground-based telescopes, a decision that has so far proven to be problematic. Though adaptive optics can eliminate some of the fuzziness caused by the atmosphere, it limits observations to very narrow fields of view, meaning it cannot obtain large mosaics of big objects, such as this Hubble release earlier this week of an image of the nearby Triangulum Galaxy. Moreover, almost all of the giant ground-based telescopes built so far have struggled with many engineering issues.

In terms of astronomy, we are thus about to go blind, returning to the days prior to the space age when our view of the heavens was fuzzy and out of focus.

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Nancy Roman passes away at 93

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R.I.P. Nancy Roman, NASA’s first chief astronomer, died on Christmas at the age of 93.

Her name is largely forgotten, but her support for building the Hubble Space Telescope in the 1960s and the 1970s was critical in getting it done. As important, her support for all in-space astronomy in these early years eventually made it possible. During her term NASA built and launched the first space telescopes. Some were duds. Some were incredible successes. Regardless, her leadership proved that astronomy in space made sense, leading to the achievements that have followed in the half century that has followed.

God speed, Nancy Roman.

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