Tag: astronomy

Pluto’s moons rotate chaotically

12:33 pm

Data from the Hubble Space Telescope has determined that two and maybe more of Pluto’s moons have chaotic rotations.

In a surprising new study, it has been found that two of Pluto’s moons, Nix and Hydra, are in a chaotic rotation. This means that an observer on Pluto would not see the same face of the moons from one night to the next. For visitors on the moons themselves, things would get even more confusing, as every day would be a different length to the one that preceded it. The other two moons studied, Kerberos and Styx, will likely be found to be chaotic too, pending further study.

This would also mean that you would not know where on the horizon the sun or Pluto would rise each day.

This information was gathered partly to help New Horizons prepare for its July 14 fly-by.

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Astronomers accept terms imposed on them by protesters in Hawaii

5:40 pm

The University of Hawaii, which manages the astronomy operation on Mauna Kea, has accepted the terms laid down by the state’s governor for allowing construction of the Thirty Meter Telescope.

Essentially the number of telescopes on the peak will have to be reduced above and beyond the original decades-old agreement, and the University will have to find money to pay for these “native” programs:

Improved cultural research, education and training: We will work with Kahu Kū Mauna and other Native Hawaiian advisors to develop new cultural training and educational programs about Maunakea. Training is currently required for people working on the mountain and we will look for opportunities for improvement. We will develop training and education programs for visitors to ensure that all who come to Maunakea understand its cultural significance and how to respect the mountain. To ensure our cultural training and education programs are accurate, effective and continuing, we will establish at UH Hilo a new program to lead and evaluate our expanded cultural stewardship and educational activities related to Maunakea. …

New scholarship programs: The governor asked TMT to increase its support to Native Hawaiian students, particularly those from Hawaiʻi Island, who wish to pursue science and technology careers. UH recognizes its responsibilities in this area and we will launch a campaign for new scholarship programs for Hawaiʻi Island and Native Hawaiian students to increase their participation in the sciences. The university will allocate a portion of its observing time to UH Hilo for use in projects and programs to support greater participation and improved preparation of Hawaiʻi Island students for professional careers.

The first will essentially buy off the leaders of the protesters, hiring them to pound into outsiders the wonderfulness of native culture. The second, though it will provide educational scholarships — a good thing — is still essentially bigoted and discriminatory in that it determines who shall get the scholarships solely by their ethnic origin. Imagine the reaction if a university in the U.S. offered a comparable scholarship only to whites.

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ALMA detects a solar flare on Mira 420 light years away

9:17 am

Mira A and Mira B

The just completed ALMA (Atacama Large Millimeter/submillimeter Array), a collection of 66 antennas located in Chile, has snapped a picture of the variable star Mira with its companion star, detecting details on the primary’s surface, including evidence of a solar flare.

Mira is a star with a mass like our Sun’s, but near the end of its life having evolved into a red giant that is shedding its outer layers. Being able to track its behavior with this kind of detail will allow astronomers to better hone their theories about the life and death of stars, including our own.

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A solar system like our own, but when it was a baby

9:28 am

Astronomers have discovered a very young 15 million year old star only 360 light years away that has a debris disk about the size of our solar system’s Kuiper Belt.

The ring is about the same distance from its parent star as the Kuiper belt is from the Sun, and receives roughly the same amount of light. Its blue-grey colour hints that it could consist of ices and rocky silicates such as those found in the Kuiper belt, says lead author Thayne Currie, an astronomer at the Subaru Telescope in Hawaii, which is run by the National Astronomical Observatory of Japan. “This is absolutely the closest example we have of a young Kuiper belt,” he says.

The best part of this discovery however might be how it was made, by using a new instrument on the ground-based Gemini telescope on Mauna Kea in Hawaii.

The instrument, which is part of the Gemini South telescope in Chile, uses a disk called a coronagraph to blot out the glare of bright stars. That allows it to take multi-wavelength pictures of faint, orbiting planets and debris disks around stars, by recording near-infrared light from the parent star as it scatters off the debris. The researchers discovered the disk around HD 115600 fewer than 6 months after the GPI began operation. A similar instrument, known as SPHERE, began operating in May 2014 on the European Southern Observatory’s Very Large Telescope in Chile and has also begun to make discoveries.

Assuming protesters don’t force Gemini to close, we should be getting a lot more exoplanetary discoveries from it in the coming years.

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Hubble films of movie of a jet firing from a black hole

12:38 pm

Cool image time! Using images taken by the Hubble Space Telescope over the past two decades astronomers have assembled a movie of the motion of blobs, ejected by a jet from a supermassive black hole at the center of a galaxy.

The jet from NGC 3862 has a string-of-pearls structure of glowing knots of material. Taking advantage of Hubble’s sharp resolution and long-term optical stability, Eileen Meyer of the Space Telescope Science Institute (STScI) in Baltimore, Maryland, matched archival Hubble images with a new, deep image taken in 2014 to better understand jet motions. Meyer was surprised to see a fast knot with an apparent speed of seven times the speed of light catch up with the end of a slower moving, but still superluminal, knot along the string. The resulting “shock collision” caused the merging blobs to brighten significantly.

The movie is below the fold.
» Read more

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Hawaii’s governor imposes new deal for Mauna Kea

10:29 am

In his effort to appease the protesters hostile to building the Thirty Meter Telescope (TMT) on Mauna Kea, Hawaii’s Democratic governor has thrown out the decades-old agreement that had guided telescope construction there and has instead imposed a new deal, which will allow for TMT but will force astronomers to remove one quarter of the other telescopes on the mountain.

Astronomers have always honored the original agreement, allowing the construction of no more than 13 telescopes on the mountain. For example, to build TMT the Caltech Submillimeter Observatory was to be removed this year. Now they will have to remove some additional telescopes that had been built with the understanding that they could remain there, based on the original agreement.

The governor’s plan will also limit access to the mountain by non-natives, and require visitors to receive “cultural training”, likely a session explaining the sacredness of the native religion and how it must be obeyed at all times.

To my mind this new deal is another indication of the slow retreat of western civilization in the U.S. Once again our ability to push the unknown will be limited in favor of fostering the superiority of one ethnic group over another.

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Prototype variable star has a previously unknown companion

10:51 am

The uncertainty of science: The star that gave its name to the class of variable stars called Cepheid variables — used by astronomers to measure distances to nearby galaxies — has after more than 200 years of study been suddenly found to be a binary system.

Delta Cephei, prototype of the cepheids, which has given its name to all similar variable stars, was discovered 230 years ago by the English astronomer John Goodricke. Since the early 20th century, scientists have been interested in measuring cosmic distances using a relationship between these stars’ periods of pulsation and their luminosities (intrinsic brightness), discovered by the American Henrietta Leavitt. Today, researchers from the Astronomical Observatory of UNIGE, Johns Hopkins University and the ESA show that Delta Cephei is, in fact, a double star, made up of a cepheid-type variable star and a companion that had thus far escaped detection, probably because of its low luminosity. Yet, pairs of stars, called binaries, complicate the calibration of the period-luminosity relationship, and can bias the measurement of distances. This is a surprising discovery, since Delta Cephei is one of the most studied stars, of which scientists thought they knew almost everything. [emphasis mine]

This discovery illustrates the shaky foundation of a great deal of astronomical research. The presence of a companion is an additional variable that could very significantly skew the relationship between the stars’ pulses and its luminosity, thus making the use of this data to determine distance much less reliable. This in turn could have a significant effect on the present estimate of the expansion rate of the universe, which in turn could have a significant effect on the theories of dark energy. Moreover, if the past distance estimates to many objects are wrong than what we know about those objects is far less certain.

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Mysterious X-rays at the center of the galaxy

9:07 am

The uncertainty of science: The x-ray space telescope NuSTAR has detected high energy x-rays at the center of the Milky Way coming from no obvious source.

In and of themselves, X-rays from the galactic center aren’t unusual. But the X-rays NuSTAR detects don’t seem to be associated with structures already known to exist. For example, a supernova remnant named Sgr A East emits low-energy X-rays but not high-energy X-rays. The high-energy blotch doesn’t correlate with structures seen in radio images either, such as the dust and gas clouds of Sgr A West that are falling toward the supermassive black hole.

Instead, Perez and her colleagues propose that thousands of stellar corpses could be responsible for the high-energy X-rays: massive (and still-growing) white dwarfs, spun-up pulsars, or black holes or neutrons stars feeding on low-mass companion stars.

All of their proposed solutions, however, have serious problems explaining all of the data.

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An exoplanet that shouldn’t exist

10:06 am

Worlds without end: Astronomers have discovered an exoplanet that is too big for its tiny host star.

Present theory says that a Jupiter-sized planet should not have formed around this M-class dwarf star. But it has. In addition, the planet has the mass of Saturn but has been puffed up to the size of Jupiter. Yet, the star doesn’t provide it enough heat to cause it to puff up in this manner.

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Hawaii agency withdraws support for TMT

9:47 am

Maybe it is time to get out: The Office of Hawaiian Affairs (OHA), which had approved the Thirty Meter Telescope (TMT) in 2009, has formally withdrawn its support.

I think the testimony to OHA by the opponents of the telescope says it all:

Thursday’s vote followed a day of emotional testimony at OHA’s offices in Honolulu.


“We have compromised and negotiated 13 times already, and enough is enough,” said testifier Mehana Kihoi. She said scientists did not understand the significance of the mountain to Hawaiian people. “These are people with no sacred place, no connection, no culture,” she said. Kihoi had spent more than 28 days occupying the mountain with other protesters and choked back tears as she described the spiritual experience of being there. “When you place your hands and your bare feet into the soil, you feel that warmth, you feel her heart. At 3 a.m., when … you feel her breath come down and sit on your bones, you know that she is alive.” She called on trustees to oppose the project: “Money comes and goes; our aina [land] is forever.”

Longtime Native Hawaiian activist Walter Ritte said stopping the TMT was no longer enough and that Hawaiians needed to take a stronger stand on the mismanagement of the mountain summit. “They’ve misused it to the point that they need to get all of those telescopes off Mauna Kea,” he said. “It’s a matter of principle.” [emphasis mine]

The comments of the first woman reveal an underlying bigotry and hatred of non-Hawaiians. The comments of the second person reveal a hostility to science and the advancement of knowledge that is most striking.

My instinct is to tell them to go to hell and to pull out all the telescopes, and financial support, to the islands. Maybe a tourist boycott should be started, since they obviously find non-Hawaiians and Western culture so offensive. We’d suddenly discover that these self-righteous claims are as shallow as I’ve described, bigoted and small-minded. Suddenly Hawaiians would be begging Westerners to return to the island.

My second and stronger instinct is to also tell them to go to hell, and to push through construction so that we do not bow to this kind of bigotry.

Unfortunately, our society no longer has the courage to do either. We will bow to these demands, and bigotry will win again.

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Is it dark matter, or a previously unrecognized failure of Newton?

9:42 am

Dark matter?

The uncertainty of science: Using new data gathered by the 10-meter Keck telescope in Hawaii, astronomers have found that the outer stars of elliptical galaxies exhibit the same behavior as the outer stars of spirals, suggesting once again the existence of dark matter.

One of the most important scientific discoveries of the 20th century was that the spectacular spiral galaxies, such as our own Milky Way, rotate much faster than expected, powered by [the] extra gravitational force of invisible “dark matter” as it is now called. Since this discovery 40 years ago, we have learned that this mysterious substance, which is probably an exotic elementary particle, makes up about 85 percent of the mass in the Universe, leaving only 15 percent to be the ordinary stuff encountered in our everyday lives. Dark matter is central to our understanding of how galaxies form and evolve – and is ultimately one of the reasons for the existence of life on Earth – yet we know almost nothing about it.

“The surprising finding of our study was that elliptical galaxies maintain a remarkably constant circular speed out to large distances from their centers, in the same way that spiral galaxies are already known to do,” said Cappellari. “This means that in these very different types of galaxies, stars and dark matter conspire to redistribute themselves to produce this effect, with stars dominating in the inner regions of the galaxies, and a gradual shift in the outer regions to dark matter dominance.”

What is most fascinating about this press release, however, is that it also noted that dark matter is only one explanation for the data, and that the failure of Newtonian physics at large distances, instead of dark matter, might also provide an explanation.

However, the [solution] does not come out naturally from models of dark matter, and some disturbing fine-tuning is required to explain the observations. For this reason, the [problem] even led some authors to suggest that, rather than being due to dark matter, it may be due to Newton’s law of gravity becoming progressively less accurate at large distances. Remarkably, decades after it was proposed, this alternative theory (without dark matter) still cannot be conclusively ruled out.

Physicists call this other theory MOND, for modified Newtonian dynamics. It is not a very popular theory, however, and is almost always ignored, even though it appears to work as well as dark matter to explain the motion of stars in galaxies. Instead, most scientists favor dark matter.

For this press release to mention it as suggests the new data favors it over dark matter, which would make this a significant discovery.

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The first reflected light from an exoplanet detected

5:29 pm

For the first time scientists have detected directly the reflected light coming from an exoplanet.

Astronomers using the HARPS planet-hunting machine at ESO’s La Silla Observatory in Chile have made the first-ever direct detection of the spectrum of visible light reflected off an exoplanet. These observations also revealed new properties of this famous object, the first exoplanet ever discovered around a normal star: 51 Pegasi b. The result promises an exciting future for this technique, particularly with the advent of next generation instruments, such as ESPRESSO, on the VLT, and future telescopes, such as the E-ELT.

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Hubble finds something astronomers can’t explain

8:41 am

The uncertainty of science: The Hubble Space Telescope has spotted the explosion of a star that does not fit into any theory for stellar evolution.

The exploding star, which was seen in the constellation Eridanus, faded over two weeks — much too rapidly to qualify as a supernova. The outburst was also about ten times fainter than most supernovae, explosions that destroy some or all of a star. But it was about 100 times brighter than an ordinary nova, which is a type of surface explosion that leaves a star intact. “The combination of properties is puzzling,” says Mario Livio, an astrophysicist at the Space Telescope Science Institute in Baltimore, Maryland. “I thought about a number of possibilities, but each of them fails” to account for all characteristics of the outburst, he adds.

We can put this discovery on the bottom of a very long list of similar discoveries by Hubble, which this week is celebrating the 25th anniversary of its launch.

On that note, as part of that celebration Space.com today has published a long interview with me about Hubble and my book, The Universe in a Mirror, the saga of the Hubble Space Telescope and the visionaries who built it. They have also published an excerpt from the book. Check both out.

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TMT construction postponed again

7:49 am

The builders of the Thirty Meter Telescope have temporarily extended the suspension of construction originally demanded by Hawaii’s governor.

The tone of the article, especially the comments by the governor, suggests that the state is accepting the reality that they have no legal right to stop construction, and are making that fact very public. Instead, the govenor is now beginning the public relations campaign to make construction possible despite the protests, including negotiating some other givebacks to the protesters to shut them up. Sadly, those giveback appear to be the decommissioning of some other working telescopes as well as some increased restrictions on access to the mountain by the public.

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No obvious evidence of advanced civilizations in 100,000 galaxies

10:57 pm

A search for evidence of advanced civilizations in the WISE orbiting telescope database has come up mostly empty.

Theoretical physicist Freeman Dyson proposed in the 1960s that advanced alien civilizations beyond Earth could be detected by the telltale evidence of their mid-infrared emissions. It was not until space-based telescopes like the WISE satellite that it became possible to make sensitive measurements of this radiation emitted by objects in space.

Roger Griffith, a postbaccalaureate researcher at Penn State and the lead author of the paper, scoured almost the entire catalog of the WISE satellite’s detections — nearly 100 million entries — for objects consistent with galaxies emitting too much mid-infrared radiation. He then individually examined and categorized around 100,000 of the most promising galaxy images. Wright reports, “We found about 50 galaxies that have unusually high levels of mid-infrared radiation. Our follow-up studies of those galaxies may reveal if the origin of their radiation results from natural astronomical processes, or if it could indicate the presence of a highly advanced civilization.”

Though the spin of the article is that no clear evidence of alien civilizations was found, I am most intrigued by those 50 candidate galaxies.

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Ground-breaking for LSST takes place in Chile

3:12 pm

The official launch of construction of the Large Synoptic Survey Telescope (LSST) took place today in Chile.

Today, collaborators from the U.S. National Science Foundation (NSF), U.S. Department of Energy (DOE), Chile’s Ministry of Foreign Affairs and Comisión Nacional de Investigación Científica y Technológica (CONICYT) and several other international public-private partners will gather outside La Serena, Chile, for a traditional Chilean stone-laying ceremony to celebrate the construction launch of the Large Synoptic Survey Telescope (LSST).

They did the same kind of ceremony in Hawaii for the ground-breaking of the Thirty Meter Telescope, but things have gone very sour since. In Chile, however, I expect no problems. I wonder which local community has more sense.

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Dark energy evidence found to be uncertain

10:10 am

The uncertainty of science: Astronomers have discovered that the type of supernovae they have used as a standard to measure the accelerating expansion of the universe, which also is evidence for the existence of dark energy, are actually made up of two different types.

The authors conclude that some of the reported acceleration of the universe can be explained by color differences between the two groups of supernovae, leaving less acceleration than initially reported. This would, in turn, require less dark energy than currently assumed. “We’re proposing that our data suggest there might be less dark energy than textbook knowledge, but we can’t put a number on it,” Milne said. “Until our paper, the two populations of supernovae were treated as the same population. To get that final answer, you need to do all that work again, separately for the red and for the blue population.”

The authors pointed out that more data have to be collected before scientists can understand the impact on current measures of dark energy.

It has always bothered me that the evidence for dark energy was based entirely on measurements of type 1a supernovae from extremely far away and billions of years ago. Not only was that a different time in the universe’s history when conditions could be different, our actual understanding of those supernovae themselves is very tenuous. We really do not have a full understanding of what causes them, or how they even happen. To then assume that these distant explosions are all so similar that their brightness can be used as a “standard” seems untrustworthy. From my perspective, the conclusions, though interesting, are being pushed based on extremely weak data.

The research at the link illustrates just how weak that data was.

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Hawaii governor extends halt to construction of telescope

9:18 am

Bowing to extortion: The governor of Hawaii has extended her stop order on the construction of the Thirty Meter Telescope at Mauna Kea because of the protests of about 30 people.

I am sorry, but I remain very skeptical about the real motives of most of these protesters. In every previous example, the reasons for the protests always vanished as soon as the protesters got a deal and some cash for their trouble. I suspect this is what is going to happen this time as well.

They aren’t protecting their “sacred site” on Mauna Kea. They are using the sacredness of the site to extort cash and favors from the state and the telescope operation.

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New studies struggle to explain the origin of the Moon

10:03 am

The uncertainty of science: Three new studies on the mystery of the origin of the Moon all appear to better confirm the theory that it was created when the Earth collided with a Mars-sized planet.

It is important to be aware of the uncertainties here. All these studies were done to try to address problems with the impact theory, and though they kind of answer the questions, they leave behind some important doubts.

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Governor orders one week shut down of Thirty Meter Telescope project

8:46 am

Bowing to the demands of about two dozen protesters, the governor of Hawaii has ordered a one week halt in the construction of the Thirty Meter Telescope (TMT) on Mauna Kea.

You can read statements from the governor, the protesters, and the telescope’s project manager here. Make sure especially you read the statement by the telescope manager, as it outlines in great detail the negotiations over the past seven years between the telescope and the local community. This project was not forced upon them. They discussed it and agreed to it. As the statement notes,

Following an appeal of the permit and further contested case proceedings, the TMT project has proceeded in full compliance with the law. The TMT site was selected with great care and respect. There are no archaeological shrines or burial sites within TMT’s project site. Comprehensive research by expert hydrologists confirm there is no threat to the aquifer.

This is the same story we’ve seen for the past half century with every telescope that has been built in territories where the local native population has some say in construction. Years of negotiation are ignored just as construction is about to begin by a small number of protesters demanding a halt. The protesters always claim a combination of religious and environmental concerns. In every case, these so-called passionate demands somehow vanish after they are promised some additional cash.

It would a terrible tragedy for Hawaii, and the human race, if this $1.4 billion telescope ends up getting canceled because of the complaints of a handful of people who to my mind are behaving like extortionists. It will also be unfortunate if the government bows to this extortion and rewards them for this behavior.

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ALMA captures the rotation of the large asteroid Juno

8:52 am

The large ground-based telescope ALMA has captured a series of images of the large asteroid Juno, allowing scientists to estimate its rotation and overall shape.

Linked together into a brief animation, these high-resolution images show the asteroid rotating through space as it shines in millimeter-wavelength light. “In contrast to optical telescopes, which capture the reflected light from the Sun, the new ALMA images show the actual millimeter-wavelength light emitted by the asteroid,” said Todd Hunter, an astronomer with the National Radio Astronomy Observatory (NRAO) in Charlottesville, Va.

…The complete ALMA observation, which includes 10 separate images, documents about 60 percent of one rotation of the asteroid. It was conducted over the course of four hours on 19 October 2014 when Juno was approximately 295 million kilometers from Earth. In these images, the asteroid’s axis of rotation is tilted away from the Earth, revealing its southern hemisphere most prominently.

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Dark matter is even more of a mystery that expected

4:36 pm

The uncertainty of science: Using the Hubble and Chandra space telescopes astronomers have discovered that dark matter is not only invisible to direct observation, it is invisible to itself!

In this new research, Harvey and his team realized just how invisible this stuff is, even to itself. As two galactic clusters collide, the stars, gas and dark matter interact in different ways. The clouds of gas suffer drag, slow down and often stop, whereas the stars zip past one another, unless they collide — which is rare. On studying what happens to dark matter during these collisions, the researchers realized that, like stars, the colliding clouds of dark matter have little effect on one another.

Thought to be spread evenly throughout each cluster, it seems logical to assume that the clouds of dark matter would have a strong interaction — much like the colliding clouds of gas as the colliding dark matter particles should come into very close proximity. But rather than creating drag, the dark matter clouds slide through one another seamlessly.

I guarantee that this result is not definitive. The data here is on the very edge of reality, built on too many assumptions. We know that something undetected as yet is influencing the motions of galaxies, but what exactly it is remains completely unknown. These results only make the mystery more mysterious.

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GAO denied access to Webb telescope workers by Northrop Grumman

11:04 pm

In a report as well as at House hearings today the GAO reported that Northrop Grumman has denied them one-on-one access to workers building the James Webb Space Telescope.

The interviews, part of a running series of GAO audits of the NASA flagship observatory, which is billions of dollars overbudget and years behind schedule, were intended to identify potential future trouble spots, according to a GAO official. But Northrop Grumman Aerospace, which along with NASA says the $9 billion project is back on track, cited concerns that the employees, 30 in all, would be intimidated by the process.

To give Northrop Grumman the benefit of the doubt, these interviews were a somewhat unusual request. Then again, if all was well why would they resist? Note too that the quote above says the cost of the telescope project is now $9 billion. That’s a billion increase since the last time I heard NASA discuss Webb. If the project was “back on track: as the agency and Northrop Grumman claim, than why has the budget suddenly increased by another billion?

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Ganymede’s underground salt water ocean

9:33 am

By measuring the interaction of Jupiter and Ganymede’s magnetic fields, scientists have been able to estimate the size of the salt water ocean in Ganymede’s interior.

A team of scientists led by Joachim Saur of the University of Cologne in Germany came up with the idea of using Hubble to learn more about the inside of the moon. “I was always brainstorming how we could use a telescope in other ways,” said Saur. “Is there a way you could use a telescope to look inside a planetary body? Then I thought, the aurorae! Because aurorae are controlled by the magnetic field, if you observe the aurorae in an appropriate way, you learn something about the magnetic field. If you know the magnetic field, then you know something about the moon’s interior.”

If a saltwater ocean were present, Jupiter’s magnetic field would create a secondary magnetic field in the ocean that would counter Jupiter’s field. This “magnetic friction” would suppress the rocking of the aurorae. This ocean fights Jupiter’s magnetic field so strongly that it reduces the rocking of the aurorae to 2 degrees, instead of 6 degrees if the ocean were not present. Scientists estimate the ocean is 60 miles (100 kilometers) thick — 10 times deeper than Earth’s oceans — and is buried under a 95-mile (150-kilometer) crust of mostly ice.

That’s more water than contained in all of Earth’s oceans.

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