Tag: astronomy

New Hubble image of Crab Nebula

9:42 am

Crab Nebula

Cool image time! Scientists have released a new Hubble Space Telescope image taken of the innermost regions of the Crab Nebula, the remains of a supernova explosion that took place a thousand years ago in 1054.

On the right is a reduced resolution version of this new image. I have also cropped it to focus on the nebula’s center, where the pulsar is located. The circular concentric rings are exactly what they appear to be, ripples of energy spreading out from the pulsar. Back in 2002 Hubble took a series of images of the Crab Nebula over several days, which scientists then assembled into a movie showing these waves as they emanated out from the nebula’s center.

My only complaint with this beautiful new image is that they did not take a longer series of new exposures to create a longer movie, to better show the actual daily changes that the nebula undergoes. It seemed obvious to do then, and obvious to do now. Yet, it hasn’t happened.

The image download page for today’s release is here.

0 comments

Hubble images Jupiter and its aurora

9:03 am

Jupiter and its aurora

Cool image time! In anticipation of the arrival of Juno in orbit around Jupiter on July 4, scientists have released a spectacular image of Jupiter and its aurora, taken by the Hubble Space Telescope. The image on the right has been reduced slightly to fit on the webpage.

The main focus of the imaging is the aurora.

To highlight changes in the auroras, Hubble is observing Jupiter almost daily for several months. Using this series of far-ultraviolet images from Hubble’s Space Telescope Imaging Spectrograph, it is possible for scientists to create videos that demonstrate the movement of the vivid auroras, which cover areas bigger than the Earth.

Not only are the auroras huge in size, they are also hundreds of times more energetic than auroras on Earth. And, unlike those on Earth, they never cease. While on Earth the most intense auroras are caused by solar storms — when charged particles rain down on the upper atmosphere, excite gases, and cause them to glow red, green, and purple — Jupiter has an additional source for its auroras.

The strong magnetic field of the gas giant grabs charged particles from its surroundings. This includes not only the charged particles within the solar wind, but also the particles thrown into space by its orbiting moon Io, known for its numerous and large volcanos.

I have embedded below the fold one of the videos of the aurora, taken over time by Hubble. Quite amazing.
» Read more

3 comments

Moon discovered orbiting Kuiper Belt Object Makemake

6:57 pm

Worlds without end: Astronomers have discovered a moon orbiting Makemake, the fouth largest object in the Kuiper Belt.

A nearly edge-on orbital configuration helped it evade detection, placing it deep within the glare of the icy dwarf during a substantial fraction of its orbit. Makemake is one of the largest and brightest known Kuiper Belt Objects (KBOs), second only to Pluto. The moon is likely less than 100 miles wide while its parent dwarf planet is about 870 miles across. Discovered in 2005, Makemake is shaped like football and sheathed in frozen methane.

Tracking this moon’s orbit will help astronomers get a better understanding of Makemake itself, whose oblong shape has baffled them since its discovery.

0 comments

Hubble lives on!

1:58 pm

NASA has extended the contract with the Space Telescope Science Institute in Baltimore, Maryland to operate the Hubble Space Telescope for another five years, through 2021.

Launched in 1990 and repaired for the first time in 1993, Hubble appears likely to operate for more than three decades, a stunning record for any spacecraft.

4 comments

Newly discovered asteroid quasi-moon of Earth

11:41 pm

A newly discovered asteroid has a solar orbit that makes it Earth’s constant companion.

As it orbits the sun, this new asteroid, designated 2016 HO3, appears to circle around Earth as well. It is too distant to be considered a true satellite of our planet, but it is the best and most stable example to date of a near-Earth companion, or “quasi-satellite.”

“Since 2016 HO3 loops around our planet, but never ventures very far away as we both go around the sun, we refer to it as a quasi-satellite of Earth,” said Paul Chodas, manager of NASA’s Center for Near-Earth Object (NEO) Studies at the Jet Propulsion Laboratory in Pasadena, California. “One other asteroid — 2003 YN107 — followed a similar orbital pattern for a while over 10 years ago, but it has since departed our vicinity. This new asteroid is much more locked onto us. Our calculations indicate 2016 HO3 has been a stable quasi-satellite of Earth for almost a century, and it will continue to follow this pattern as Earth’s companion for centuries to come.”

The asteroid is thought to be between 120 to 300 feet across.

3 comments

National Science Foundation considers shuttering Arecibo

9:33 am

Faced with tight budgets, the National Science Foundation (NSF) is considering several options for the future operation of the Arecibo Observatory, the world’s largest single radio telescope dish, including its complete removal.

[T]he NSF could mothball the site, shutting it down in such a way that it could restart (sometime in the future). Or it could dismantle the telescope altogether and restore the area to its natural state, as required by law if the agency fully divests itself of the observatory and closes it. Previous studies have said such a process could cost around $100 million—more than a decade’s worth of its current funding for telescope operations. Jim Ulvestad, director of the NSF Division of Astronomical Sciences, says the agency is still investigating, not concluding. “No alternative has been selected at this juncture,” he says. And much consideration will go into the final financial decision, whatever it may be. Some outside the agency see writing on the wall. “NSF is dead serious about offloading Arecibo funding to someone else—anyone else,” says Ellen Howell, a former staff scientist at Arecibo and now a faculty member at the Lunar and Planetary Laboratory (LPL) in Tucson, Arizona.

The article spends a lot of time talking about how wonderful Arecibo is, but never tells us how many astronomers actually demand to use it. Is it oversubscribed, like Hubble, where five times the number of astronomers request time than can be handled, or does it often sit unused because not enough astronomers require its use? NSF and the government do not have unlimited funds, and need to focus their spending where the demand is. If Arecibo is not in demand, then they are wise to consider closing it, or handing it off to someone who wants it.

3 comments

LISA Pathfinder proves space-based gravity wave detection technology

8:43 am

Engineers have announced that the gravity wave detection technology being tested in orbit by Europe’s LISA Pathfinder works.

To show that the necessary sensitivity is possible, LISA Pathfinder measures the distance between two masses, both of which are inside the spacecraft. “We’ve shrunk the arm of a large gravitational wave antenna to 35 centimeters so we could show it works properly,” Paul McNamara, LISA Pathfinder project scientist, told the press conference.

LISA Pathfinder was launched in December 2015 to a spot 1.5 million kilometers from Earth. When its test masses where first released to float free in February, “the relief was unbelievable,” McNamara says. Science operations began on 1 March and on that first day the team was able to measure distance variations between the masses much smaller than LISA Pathfinder’s mission requirements, Stefano Vitale, the mission’s principle investigator, told reporters. After a month, the variations were even smaller, “very close to [eLISA] requirements,” he says.

They now hope to launch an array of at least three such spacecraft by the mid-2030s.

0 comments

Titan over Saturn’s rings

9:35 am

Titan over Saturn's rings

Cool image time! The picture on the right, taken on January 26, 2016 by Cassini and reduced and cropped to show here, captures Titan above Saturn’s rings, which are themselves partly obscured by the shadow of Saturn (unseen on the right) that falls across them.

Make sure you go to look at the full image. This is the kind of vista that artists in the 1950s imagined we’d see once we began to explore the solar system.

0 comments

Hawaii turns down requests to remove TMT hearings officer

9:10 am

The state of Hawaii has decided to not replace the hearings officer in charge of the new permitting process for the Thirty Meter Telescope, despite a request by TMT to remove her.

There are different reasons for wanting to replace her. Telescope opponents raise conflict-of-interest concerns over her paid family membership to the Imiloa Astronomy Center. The university takes issue with her mediating another matter involving the Manoa campus. The nonprofit telescope company says replacing her with an alternate would avoid further delay.

“With due respect and consideration to the parties’ various interests and reasons for asking the board to replace Judge Amano, the board cannot and will not sidestep its own administrative responsibility to exercise judgment and common sense regarding whether the selection process up until now has objectively appeared to be fair,” the order said. “Common sense must prevail.”

The situation is a strange one. Despite the fact that the judge would likely rule fairly, TMT wanted her removed because they expect their opponents to eventually dispute any favorable decision she makes because of her link to the astronomy center. By refusing to remove her, the state is actually taking the side of the telescope’s opponents, since their main tactic is delay.

I hope TMT’s builders are making serious plans for finding an alternative site. I do not expect them to ever get permission to build in Hawaii.

0 comments

New data challenges consensus on galaxy formation

8:54 am

The uncertainty of science: A new study has found that the accepted consensus for the formation of large elliptical galaxies does not work, and that, rather than forming from the merger of smaller spiral galaxies, ellipticals formed in place from the material at hand.

From the press release [pdf].

“We started from the data, available in complete form only for the closer galaxies and in incomplete form for the more distant ones, and we filled the ‘gaps’ by interpreting and extending the data based on a scenario we devised” comments Mancuso. The analysis also took into account the phenomenon of gravitational lensing, which allows us to observe very distant galaxies belonging to ancient cosmic epochs.

In this “direct” manner (i.e., model-independent) the SISSA group obtained an image of the evolution of galaxies even in very ancient epochs (close, in a cosmic timescale, to the epoch of reionization). This reconstruction demonstrates that elliptical galaxies cannot have formed through the merging of other galaxies, “simply because there wasn’t enough time to accumulate the large quantity of stars seen in these galaxies through these processes”, comments Mancuso. “This means that the formation of elliptical galaxies occurs through internal, in situ processes of star formation.

The important take-away of this result is that it shows that the present theory of galaxy formation, where smaller spiral galaxies merge to form larger elliptical galaxies, does not fit the data. And if a theory does not fit the data, it must be abandoned.

5 comments
1 … 103 104 105 106 107 … 188