Universe Today

October 10, 2007December 26, 2015 by Fraser Cain

First Pictures From Kaguya

The Japanese space agency JAXA has confirmed that their lunar orbiter Kaguya (aka Selene) is now firmly in orbit around the Moon. That was quick. The agency released this image captured by Kaguya’s high-gain antenna motor camera showing its new home.

The spacecraft isn’t due to take photographs with its full suite of scientific instruments until it reaches its final science orbit later this month. This image was captured by the antenna motor, which just happens to have a view of the Moon in the background. Don’t worry, the images are going to get much, much better.

By the time Kaguya is in its final science orbit, it will be able to capture images of the lunar surface at a resolution of 1-metre. It will also be recording high-definition television images of the surface, which should look just amazing in the eventual documentaries.

Original Source: JAXA News Release

October 10, 2007January 24, 2021 by Fraser Cain

Astrosphere for October 10th, 2007

First, your photo for the day is of the Trifid Nebula, captured by JAICOA.

In Universe Today news, I’m testing out a new forum/blogging software called Lefora. This could be an eventual new home for Universe Today, or maybe it’ll be a botched experiment, quickly forgotten. To help me decide, please take a moment and come check it out at: http://universetoday.lefora.com/. Register as a user, comment on stories, start new discussions, post pictures, vote. And give your feedback. I’d really appreciate your help.

Now, onto the ‘sphere.

As a tribute for the 100,000th asteroid discovery, researchers have decided to rename it to Astronautica.

SPACE.com has a video of a potential asteroid mission.

Astronomy.com reports on the battle to save the Arecibo observatory.

Australian researchers are working on a design for a self-sufficient lunar colony.

Didn’t you think it was cool that Google redesigned its logo to celebrate Sputnik’s 50th anniversary? Not everyone did, apparently.

No, that’s not a big glass worm on the surface of Mars.

Remember the DARPA Grand Challenge, where robotic cars navigated a complex track? The urban version is about to begin. Robotic cars on busy city streets. I can’t wait.

And finally, Centauri Dreams remembers Robert Bussard, inventor of the ram jet that bears his name. He passed away from cancer a few days ago.

October 10, 2007December 26, 2015 by Nicholos Wethington

The Tiger Stripes and Geysers are Linked on Enceladus

Saturn’s moon Enceladus is one of the most peculiar objects in the Solar System. We now know there are geysers of water ice blasting from its southern pole; a place marked with long gashes that researchers have dubbed “tiger stripes”. Ever since the geysers were first discovered, scientists have been puzzling out their source. Now they understand how the geysers and tiger stripes are linked.

New research by the Cassini imaging team, CICLOPS, shows that the jets of Enceladus emanate from its southern pole, pouring out of four of the tiger stripes. The researchers have named them Alexandria, Cairo, Baghdad and Damascus. Of the four, Baghdad and Damascus are the most active and Alexandria is the least.

By taking Cassini’s two-year observations of the jets that spray from the surface, and combining this with thermal imaging of the stripes, the team was able to determine that the jets were spraying vertically out of the stripes, which are cracks on the surface of Enceladus.

The water sprays through the cracks because the gravity of Saturn pulls and pushes on Enceladus, and this motion – called a tidal force – heats up the frozen water underneath the surface. Much like geysers on Earth, the water is heated and expands below the surface, and follows the easiest path it can find to escape; this path happens to be right through the tiger stripes on the surface.

The researchers noted that when the tidal pull of Saturn was compressing this region of Enceladus, the geysers were not very active, if at all. But when the tides pulled and created tension, they began to erupt. Also, the hotter the region was, the stronger and larger the jet plume tended to be.

There may be other areas of Enceladus capable of producing jets, and now that the origins of the geysers are confirmed, more thermal and digital imaging of the surface could reveal other geysers in the future.

The researcher paper, entitled “Association of the jets of Enceladus with the warmest regions on its south-polar fractures” was published in the October 11th edition of the journal Nature.

Source: Nature

October 9, 2007December 26, 2015 by Fraser Cain

New Horizons Makes Surprising Discoveries at Jupiter

Remember when New Horizons sped past Jupiter on its way to Pluto. It kept its cameras rolling during the flyby, and captured hard drives full of data. Researchers have had a chance crunch through some of this data, and announced a series of discoveries this week: polar lightning storms, clumpy rings, volcanic eruptions on Io, and more.

New Horizon’s goal may be Pluto, but it’s got some time to kill between now and then. Might as well gather some science along the way. The spacecraft sped past Jupiter on February 28, 2007, picking up a valuable gravity assisted speed boost. It was the 8th spacecraft to make a close encounter with Jupiter, and just those before, it revealed valuable new insights into Jupiter and its satellites.

When the spacecraft was approaching Jupiter, mission planners carefully planned out 700 observations they wanted New Horizons to make. In fact, this is twice the number planned for the brief flyby of Pluto in 2015. They focused their collection on outstanding scientific issues that needed further investigation; to try and give scientists some kind of closure to mysteries opened up by previous spacecraft flybys.

Top on the list is Jupiter’s weather. New Horizons observed the planet’s clouds using visible light, infrared and ultraviolet. They saw ammonia clouds welling up from deeper down and heat-induced lightning strikes in the polar regions – the first polar lightning seen apart from Earth.

The spacecraft also focused in on Jupiter’s tenuous rings. The detailed observations revealed clumps of material that could indicate there was a recent impact inside the rings. Just like Saturn, Jupiter has tiny moons that serve as shepherds, keeping the ring material together.

New Horizons also focused its cameras on Jupiter’s volcanic moon Io. The spacecraft observed 11 different volcanic plumes of varying size, and could see 36 hotspots on the moon in the infrared spectrum. Three of these volcanoes were seen for the very first time.

Finally, the spacecraft measured the magnetic tail that trails behind Jupiter. New Horizons saw material ejected by Io moving down the tail in large, dense, slow-moving blobs, captured in the magnetic field.

New Horizons is now halfway between the orbits of Jupiter and Saturn, and more than 1.19 billion km (743 million miles) from Earth.

Original Source: JHU APL News Release

October 9, 2007December 26, 2015 by Fraser Cain

Are We Made of Quasarstuff Too?

Carl Sagan noted that we’re all made of starstuff; the elements fused together in stars and detonating supernovae. But maybe we’re made of something else too, outflowing dust from actively feeding supermassive black holes – known as quasars – that populated the early Universe. New observations made by NASA’s Spitzer Space Telescope has found evidence of dust pouring out of distant quasars. Dust that might have gone on to form more complex molecules, and even life. We’re all made of quasarstuff?

Our Sun formed in a region of the Milky Way enriched by the deaths of massive stars. As these monsters detonated as supernovae, they created the heavier elements and spread them far and wide around the region. But what about the early Universe, before generations of massive stars had a chance to live and then die as supernovae? Where did all the raw materials come from?

Researchers from the University of Manchester in the U.K. have written a new research article describing how they have discovered dust pouring out of supermassive black holes in the early Universe. Known as quasars, and bright enough to be seen clear across the Universe, these actively feeding black holes are actually quite messy. They eject more material out in polar jets than they’re actually able to consume.

And according to Spitzer, the material they’re ejecting contains plenty of complex dust. In one example, a quasar 8 billion light-years away is spewing out a mix of ingredients that make up glass, sand, marble and even precious gems like rubies and sapphires.

This is quite surprising, since the main ingredient of sand, crystalline silicate, can’t last long in space. The radiation from stars should be blasting the molecules back to a glass-like state. If there’s crystalline silicate, there must be a source replenishing it faster than the radiation can break it down. That source seems to be quasars.

It now appears that both supernovae and quasars work together to seed galaxies with heavier elements and complex molecules. So, we might not only be starstuff, we could also be quasarstuff.

Original Source: NASA/JPL/Spitzer News Release

October 9, 2007December 26, 2015 by Fraser Cain

Astrosphere for October 9th, 2007

Today’s astrophoto was captured by RickJ. It’s VdB152, a reflection nebula in the constellation Cepheus. Around the Bad Astronomy/Universe Today forums, we call it the “Star Eating Leech”.

First up, Astroprof reviews a device that can help you measure just how light polluted your skies are.

Discover Magazine has a great interview with SpaceShipOne designer Burt Rutan about his plans for private space exploration.

We saw the model rocket X-Wing destruction. Now enjoy similar destruction of a scale model Y-Wing. Come on, can’t anyone build a scale model Star Wars vehicle that doesn’t tear itself to pieces in mid-flight? Death Star anyone?

Remember that terrible accident during the testing of SpaceShipTwo? Flight is reporting that it’s going to cause delays to Virgin Galactic’s plans for tourist flights.

MSNBC’s Alan Boyle helps you locate the beautiful images he uses for Cosmic Log.

October 9, 2007December 26, 2015 by Fraser Cain

Undergrad Team Discovers 1,300 Asteroids

A team of undergrad astronomers at the University of Washington figured out how to turn an annoyance into a major discovery, uncovering 1,300 new asteroids; nearly 1 out of every 250 known objects in the Solar System. How did they pull of this feat? It was actually a side project to their actual research: searching for supernovae. The asteroids were getting in the way.

The undergrad researchers were looking through data gathered as part of the Sloan Digital Sky Survey. This is a collection of detailed images of the sky gathered by an automated 2.5-metre telescope. The researchers were looking for evidence of exploded stars, called supernovae, but asteroids kept getting in the way.

Instead of just working around the asteroids that were blocking their view, they decided to keep track of them, and see if any were unidentified. It turned out that 1,300 were brand new.

Andrew Becker, a UW research assistant professor in astronomy explains the initial frustrations, “I kept asking the students what they had found and they kept saying, ‘More asteroids. No supernovae, but lots of asteroids.'”

The undergrads developed programs that let them search through the Sloan data automatically, identifying asteroids, and helping them classify them. In addition to discovering 1,300 new asteroids, they compiled additional data on 14,000 asteroids that were already known. This allows astronomers to calculate their trajectories with better accuracy, and determine if any are a threat to the Earth in the future.

Original Source: UW News Release

October 9, 2007December 26, 2015 by Fraser Cain

A Possible Explanation for Two-Toned Iapetus

Saturn’s moon Iapetus is one of the most mysterious objects in the Solar System. It’s shaped like a football, has a strange ridge that runs along most of its equator, and it’s got vastly different hemispheres. One side is as white as driven snow, and the other side is dark as tar. Scientists think they’ve at least got an answer for this last mystery.

Even before humans sent spacecraft to Saturn, astronomers have known there’s something bizarre about Iapetus. Its brightness changed significantly depending on its facing towards the Earth. Follow up observations with spacecraft, like Voyager and Cassini showed that this was because half the moon is covered in snowy white material, while the other half is dark as night.

During its most recent flyby, NASA’s Cassini spacecraft confirmed that Iapetus is warm enough on the dark side – 127 Kelvin (-230 F) – that water vapour can slowly release from water ice. This vapour then travels around the moon, and freezes back down onto the white side. This process of vaporization and accumulation is called “thermal segregation”.

So where does the dark material come from? Astronomers think that it didn’t originate on Iapetus, but instead came from the surrounding outer moons. As Iapetus goes around its orbit, this darker material piles up on the leading hemisphere. The material heats up the surface of moon, allowing it to release the water vapour which then reforms on the other side.

Scientists describe this as a runaway process. Once it got going, both hemispheres went to extremes. The water completely boiled away from the dark side, and then accumulated on the bright side. You don’t see shades of grey, just black and white.

Thanks to Cassini’s recent flyby, planetary geologists think they’re getting a handle on the moon’s strange football shape and the equatorial ridge too, but those will come with future research papers.

Original Source: NASA/JPL/SSI News Release

October 9, 2007December 26, 2015 by Fraser Cain

The End of FUSE

I often talk about the preparation and launch of new missions to space, but every now and then I have to write about just the opposite: the end of a mission. Today’s one of those days. It’s my sad duty to report to you today that NASA’s Far Ultraviolet Spectroscopic Explorer (FUSE) is going offline later this month. But don’t think it went quietly into that dark night, engineers working with FUSE came up with an extraordinarily clever way to use the Earth’s magnetic field to re-orient the spacecraft as its gyroscopes failed, one after the other. But now they’ve run out of ways to fix the ailing spacecraft. It’s time to say goodbye.

I’ve mentioned FUSE in many stories in the past, so just in case you weren’t aware of it, I’ll give you a quick recap. FUSE was launched back in June 1999 – just a few months after I started Universe Today. It’s equipped with detectors that allow it to see at short ultraviolet light wavelengths, below the range where Hubble operates. Originally supposed to only run for 3 years, NASA ended up extending its mission 3 times.

Astronomers have produced more than 1,200 papers based on data gathered by FUSE. Because of its spectroscope, the satellite let astronomers break up the ultraviolet radiation coming from distant objects into digital “charts” that let them measure their chemical composition. FUSE discovered molecular hydrogen in the Martian atmosphere, the confirmation of a hot gas halo surrounding the Milky Way, and the first observations of nitrogen outside our Solar System.

So why is FUSE going offline? Wouldn’t NASA try and keep the spacecraft running forever, if possible? Oh, they tried all right.

Here’s the problem. Back in 2001, two of its four momentum wheels failed. These are the gyroscopic wheels that the spacecraft uses to orient itself towards objects in space. And it needed at least 3 to function properly. Clever engineers worked out a way to use magnetic bars inside the spacecraft to pull and push it against the Earth’s magnetic field.

This amazing solution allowed them to keep the spacecraft reoriented. But then another momentum wheel failed in 2004. Once again, though, engineers were able to make the magnetic solution work with just a single wheel and continue gathering data.

Finally, the spacecraft’s final momentum wheel started malfunctioning in May 2007 and completely died in July. Without the final wheel, there was no way to orient the spacecraft.

So on October 18th, 2007, engineers will shut down the control room, turn off the computers, and end communications with FUSE. And some time in the next few decades, the spacecraft will finally reenter the Earth’s atmosphere and burn up.

Thanks FUSE.

Original Source: JHU News Release

October 8, 2007December 26, 2015 by Fraser Cain

Podcast: Jupiter’s Moons

Last week we talked about Jupiter and we could sense right away it would be too much to handle. This week, we’ll talk about Jupiter’s moons – how many are there? What makes them so interesting? Is it true that the most likely place in the solar system to find life (other than Earth) is actually on one of Jupiter’s moons? Hang on tight. We’re going to cover a lot.

Click here to download the episode

Jupiter’s Moons – Show notes and transcript

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.