Tag Archives: Hubble

New Hubble images of Uranus and Neptune

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.


A Hubble Space Telescope status report

Five years after the last shuttle repair mission, the Hubble Space Telescope continues to operate almost perfectly.

Jeletic said other than a single gyro failure, the observatory is operating in near-flawless fashion five years after the final shuttle crew departed. “Batteries are fine, solar arrays are fine, all the communications equipment is fine, we don’t see any glitches with the computers, the instruments are all fine,” he said. “In fact, an interesting statistic, the Advanced Camera for Surveys, which was repaired by the astronauts during the last servicing mission, that’s actually now run longer on the repair than it did originally for the Wide Field Camera part of it.”

The ACS, like the repaired Space Telescope Imaging Spectrograph, no longer has any internal redundancy. “It’s amazing. It truly is,” Jeletic said. “Given all the things that can fail, a lot of people were hoping for one or two years of continued work with it. Now we’ve gotten over five.” Likewise, the Space Telescope Imaging Spectrograph, which also is operating in “single-string” mode, is still going strong.

When they completed the 2009 servicing mission, the goal was to give Hubble five more years of operation. They’ve done that, and are now looking to keep the telescope going till at least 2020, marking 30 years in orbit.

The only issue, not surprisingly, is the failure of one of the six gyros on board. These have traditionally been the telescope’s biggest problem, and have been replaced twice over during shuttle missions. Three of today’s six however are using a new design which will hopefully extend their life significantly.


Exoplanets with no water

The uncertainty of science: Though planet formation theories said they should have water, in looking for water on three exoplanets astronomers were surprised to discover practically none there.

The three planets, known as HD 189733b, HD 209458b, and WASP-12b, are between 60 and 900 light-years away from Earth and were thought to be ideal candidates for detecting water vapor in their atmospheres because of their high temperatures where water turns into a measurable vapor. These so-called “hot Jupiters” are so close to their star they have temperatures between 1,500 and 4,000 degrees Fahrenheit, however, the planets were found to have only one-tenth to one one-thousandth the amount of water predicted by standard planet-formation theories.

“Our water measurement in one of the planets, HD 209458b, is the highest-precision measurement of any chemical compound in a planet outside our solar system, and we can now say with much greater certainty than ever before that we’ve found water in an exoplanet,” said Nikku Madhusudhan of the Institute of Astronomy at the University of Cambridge, England. “However, the low water abundance we have found so far is quite astonishing.” Madhusudhan, who led the research, said that this finding presents a major challenge to exoplanet theory. “It basically opens a whole can of worms in planet formation. We expected all these planets to have lots of water in them. We have to revisit planet formation and migration models of giant planets, especially “hot Jupiters,” and investigate how they’re formed.”


Hubble takes an image of Comet Siding Spring and finds two jets coming off the nucleus.

Hubble takes an image of Comet Siding Spring and finds two jets coming off the nucleus.

The comet will fly past Mars on October 19 by a distance of only 84,000 miles, which makes understanding its jets crucially important for protecting the various spacecraft that orbit the red planet.


As imagined by SF authors: the Celestial Spiral

This amazing Hubble image, showing a strange spiral to the left of the bright star, is not of a galaxy. Instead, it is a binary star system where the material from one star is being sucked away from it by the other, thus producing the spiral pattern.

celestial spiral

What is most fascinating about this discovery is that this kind of phenomenon has been predicted for decades, by both astronomers and science fiction writers. Consider for example this quote from Larry Niven from his short story, The Soft Weapon, where he describes what he thinks the binary star Beta Lyrae might look like:

There was smoke across the sky, a trail of red smoke wound in a tight spiral coil. At the center of the coil was the source of the fire: a double star. One member was violet-white, a flame to brand holes in a human retina, its force held in check by the polarized window. The companion was small and yellow. They seemed to burn inches apart, so close that their masses had pulled them both into flattened eggs, so close that a red belt of lesser flame looped around them to link their bulging equators togehter. The belt was hydrogen, still mating in fusion fire, pulled loose from the stellar surfaces by two gravitional wells in conflict.

The gravity did more than that. It sent a loose end of the red belt flailing away, away and out in a burning Maypole spiral that expanded and dimmed as it rose toward interstellar space, until it turned from flame-red to smoke-red, bracketing the sky and painting a spiral path of stars deep red across half the universe.


Hubble image of face-on galaxy

Another spectacular Hubble Space Telescope image was released today, showing a face-on spiral galaxy in the Coma cluster, located about 320 million light years away. Key quote:

The galaxy, known as NGC 4911, contains rich lanes of dust and gas near its center. These are silhouetted against glowing newborn star clusters and iridescent pink clouds of hydrogen, the existence of which indicates ongoing star formation. Hubble has also captured the outer spiral arms of NGC 4911, along with thousands of other galaxies of varying sizes.

NGC 4911