Universe Today

March 14, 2008December 26, 2015 by Fraser Cain

When Will Space Traffic Control Be Necessary?

There’s an interesting story posted to the Christian Science Monitor today entitled, Does Space Need Air Traffic Control?. It’s a good question. Are there just too many spacecraft, satellites and space telescopes buzzing around the Earth at this point that collisions will be inevitable without some kind of system to manage them all?

The article describes the pileup of spacecraft currently at the International Space Station. Think about it. Endeavour just arrived for STS-123 and Europe’s new cargo ship will show up on April 3rd. There’s already a Progress supply ship docked to the station, and a Soyuz will be arriving on April 10th for a crew swap. And next year, the Japanese will be adding their automated resupply ship there as well.

With this kind of traffic to and from the station, people are starting to call for some way to regulate it. Some are hoping there’ll be an international body, like the International Civil Aviation Organization, and others think that nation-to-nation agreements will do the trick.

There’s a building consensus that space debris is becoming a real threat to future space launches. The more material up there, the better chance it could collide with future spacecraft and stations. And there’s a worry that the density of space debris could reach some dangerous point where it collides and re-collides until a band of space becomes a shrieking hail of tiny particles moving at high velocity. No spacecraft could withstand passing through that region without being torn to shreds.

You might be surprised to know that there’s currently no cooperation between nations. Last year, China fired an anti-satellite missile at dead communications satellite, and blew it into high velocity shrapnel. Other nations will now have to keep track of this belt of debris for more than a century until its orbit finally decays and it burns up.

Countries don’t inform one another when they launch spacecraft, when they change orbits, or even when they crash them back down into the Earth’s atmosphere (hopefully to burn up).

What would it take to get international cooperation to ensure that the trip up to orbit is as safe from debris as possible? Anyway, check out the article and discuss.

Original Source: Christian Science Monitor

March 14, 2008December 26, 2015 by Fraser Cain

Oxygen-Rich Supernova Remnent N132D

Not much to say, just a pretty picture of supernova remnant N132D, captured by NASA’s Chandra X-Ray Observatory. I don’t know about you, but this actually reminds me of a mysterious creature that might pass by a deep sea submersible. But nope, it’s in space, located in the Large Magellanic Cloud. In fact, it’s the brightest supernova remnant in the nearby dwarf galaxy.

As usual, an image like this is completely false colour, based on different wavelengths of X-ray radiation. The low energy X-rays are in red, the intermediate in green and the high-energy rays are in blue.

N132D may be the brightest supernova remnant, but it’s actually part of a rare class of oxygen-rich explosions. Astronomers are still trying to understand what conditions existed in the star itself to generate an explosion that spread so much heavy elements, like oxygen, into the surrounding space.

Original Source: Chandra News Release

March 14, 2008December 26, 2015 by Nancy Atkinson

Google Sky Takes You There

OK, I think I have my feet back on the ground now. But I may have gotten lost in the Small Magellanic Cloud’s Open Star Cluster. I’ve just been playing around with Google Sky, and have traveled around the universe, seeing dramatic astronomical images as never before. Anyone interested in astronomy, or those of you who just like awe-inspiring images will enjoy Google Sky. Just like Google Earth, Google Sky allows you to search for specific locations, zoom in and out of images, and pan around areas to look at nearby features. But Google Sky teams up with some of the largest ground- and space-based astronomical surveys to allow you to explore the far reaches of the universe.

You can select from the thumbnail images at the bottom of the display to bring up planets, constellations, highlights from the Hubble Space Telescope, famous stars, galaxies and nebulae, and views of the universe in the x-ray, ultraviolet and infrared. There’s also podcasts about upcoming astronomical events, and plenty of information about the images, including direct links to the Hubble’s comprehensive website about the specific image you are viewing.

What I found most interesting is the infrared images, particularly the ones from Spitzer. Initially, you see them in the visible spectrum, but then it quickly changes to infrared. Being able to compare the two spectrums is one of my favorite aspects of Google Sky. And other features allow you to play with the transparency to blend between all the different wavelengths and see how different parts of the universe light up at different wavelengths.

There’s also a view of the microwave sky from NASA’s Wilkinson Microwave Anisotropy Probe (WMAP), which shows the universe as it was 380,000 years after the big bang.

Also very interesting is the “Historical” feature, seeing the sky as drawn by Giovanni Maria Cassini (printed in 1792) showing the constellations in their classical form.

You can also use Google Sky to observe your own view of the sky, and zoom in for a closer look.

Start gallivanting around the universe with Google Sky here.

March 14, 2008December 26, 2015 by Nancy Atkinson

Cassini Survives Close Flyby of Enceladus

The Cassini spacecraftâ€™s audacious flyby of Saturn’s moon Enceladus on March 12 has provided scientists more information about the geyser-like jets of ice shooting from the moonâ€™s southern hemisphere. It also highlighted the drastic geologic differences between the moonâ€™s north and south pole. While the data collected from the geysers is still being analyzed, images from the flyby showed a north polar region that is older and pitted with fractured craters, compared to the relatively newer cracks in south pole area from which water jets are emanating. The spacecraft came within 50 kilometers (30 miles) of the surface at closest approach and 200 kilometers (120 miles) while flying through the plume.

“These new images are showing us in great detail how the moon’s north pole differs from the south, an important comparison for working out the moon’s obviously complex geological history,” said Carolyn Porco, Cassini imaging team leader. “And the success of yesterday’s daring and very low-altitude flyby means this coming summer’s very close encounter, when we get exquisitely detailed images of the surface sources of Enceladus’ south polar jets, should be an exciting ‘next big step’ in understanding just how the jets are powered.”

Cassini was traveling about 15 kilometers per second (32,000 mph) through plumes from the geysers. The flyby was designed so that Cassini’s particle analyzers could dissect the “body” of the plume for information on the density, size, composition and speed of the particles.

Cassini scientists are pouring over the data being returned, which will give them a better understanding of the unique plume environment of Enceladus and possibly how the geysers are being formed.

The images show the north polar region is much older and pitted with craters of various sizes. These craters are captured at different stages of disruption and alteration by tectonic activity, and probably from past heating from below. Many of the craters seem sliced by small parallel cracks that appear to be ubiquitous throughout the old cratered terrains on Enceladus.

Future close flybys may bring Cassini even closer to the surface of Enceladus. The spacecraft will come close to Enceladus again in August, and skim even closer to the moonâ€™s surface in October.

Original News Source: JPL Press Release

March 13, 2008December 26, 2015 by Fraser Cain

A Disk of Sand Found Orbiting a Young Binary System

It’s amazing to think that the Sun and planets formed out of a diffuse cloud of gas and dust. Somehow, the dust clung together into larger and larger particles – grains of sand. This sand then went on to become pebbles, rocks, and eventually entire planets. Well now astronomers have discovered a young star system with a disk of sand-sized particles orbiting it.

The discovery was made by Christopher Johns-Krull, assistant professor of physics and astronomy at Rice University, working with collaborators in the US, Germany, and Uzbekistan.

Astronomers have detected microscopic dust particles orbiting other stars before, but only by sensing their infrared emissions. This method isn’t precise enough to tell astronomers how big these particles become, or how far they’re orbiting from the newly forming star.

In this new study, the researchers measured the light reflected from sand orbiting a binary system called KH-15D. The stars are about 2,400 light years from Earth in the Cone nebula, and they’re a mere 3 million years old.

The researchers discovered that the Earth has a nearly edge-on view of KH-15D. From our point of view, the dusty disk mostly blocks the stars from view, but one star has an eccentric orbit that occasionally peeks up above the disk.

“We were attracted to this system because it appears bright and dim at different times, which is odd. These eclipses let us study the system with the star there and with the star effectively not there,” Johns-Krull said. “It’s a very fortuitous arrangement because when the star is there all the time, it’s so bright that we can’t see the sand.”

The team examined 12 years of data gathered by a handful of observatories around the world, and studied how light from the star was being reflected by the disk. They were able to determine the chemical composition and size of the sand-like particles.

Original Source: Rice University News Release

March 13, 2008December 26, 2015 by Fraser Cain

Meteorites Can Be Rich With the Ingredients of Life

How did life arise on Earth? How did we get from rocks and water to the abundance and variety that we see today? Perhaps the raw ingredients for life, amino acids, were delivered to Earth by a steady bombardment of meteorites. Researchers have turned up space rocks with concentrations of amino acids 10x higher than previously measured, raising hopes that the early Solar System was awash in organic material.

The study was done by Marilyn Fogel of Carnegieâ€™s Geophysical Laboratory and Conel Alexander of the Department of Terrestrial Magnetism with Zita Martins of Imperial College London and two colleagues, and will be published in Meteoritics and Planetary Science.

If you’re like me, the astronomy stuff’s fine, but the biology news is a little baffling (I forward the kids’ biology questions to my wife). Amino acids are organic molecules that form the backbone of proteins, which make much of life’s structures and drive chemical reactions in cells. Amino acids are naturally occurring, but they somehow came together to make the first proteins in the Earth’s early days.

The researchers took samples from three meteorites collected during recent expeditions to Antarctica. The meteorites are from a type called CR chondrites, which are through to contain ancient organic materials that date back to the earliest times of the Solar System. At one point, these meteorites were part of a larger “parent body”, which was later shattered by impacts.

One sample had few amino acids, but the other two had the highest concentration ever seen in primitive meteorites.

“The amino acids probably formed within the parent body before it broke up,â€ says Alexander. â€œFor instance. ammonia and other chemical precursors from the solar nebula, or even the interstellar medium, could have combined in the presence of water to make the amino acids. Then, after the break up, some of the fragments could have showered down onto the Earth and the other terrestrial planets. These same precursors are likely to have been present in other primitive bodies, such as comets, that were also raining material onto the early Earth. â€

So this points to the conclusion that the early Solar System was a much richer source of organic molecules than researchers previously believed. And the constant rain of amino acid-laden meteorites would have delivered this material to the primordial soup where life first emerged.

Exactly how the amino acids became the first proteins… that’s still one of the biggest mysteries in science.

Original Source: Carnegie Institution for Science News Release

March 13, 2008December 26, 2015 by Ian O'Neill

Could AA Tauri Hold the Biochemical Key to Extra-Terrestrial Life?

NASA’s Spitzer Space Telescope has measured huge quantities of water and organic compounds surrounding the star AA Tauri, 450 light years from Earth. AA Tauri is a young star, only a million years old, not too dissimilar to our Sun when it was a baby. What makes AA Tauri even more special is that it appears to have the “spectral fingerprint” for a system that could allow life to form. Finding a star system similar to our own, with organic compounds was always bound to cause excitement, but finding a star so close to us provides a fantastic opportunity to study AA Tauri. This will, in turn, help us understand the evolution of our own solar system and how life is able to form…

AA Tauri is slowly evolving. Gas and dust surrounds the star and recent observations suggest there are abundant organic chemicals (the ones responsible for binding together and creating amino acids). Although NASA’s announcement isn’t claiming that ET is out there (you can sit back into your seats), it is significant that a star should have all the building blocks for life as we know it laid out for the spectrometer on board Spitzer to observe.

The basic organic chemicals in question are possibly located within the “Goldilocks Zone” for planetary/life development from AA Tauri. Although AA Tauri is young, the surrounding flat disk of planetary-forming materials should eventually coalesce to form rocky bodies such as planets, asteroids and possibly gas giants (along the lines of “failed star” Jupiter). The abundance of organic chemicals and water will add to the intrigue surrounding the star.

These observations were collected by NASA’s Spitzer Space Telescope which is able to probe deep into the chemical structure of stars hundreds of parsecs from Earth. John Carr (Naval Research Laboratory, Washington) and Joan Najita (National Optical Astronomy Observatory, Tucson, Ariz.) are developing a new technique, applying Spitzer’s infrared spectrograph. The spectrograph is able to read the chemical composition of the dust contained within a protoplanetary disk. The team has been able to push Spitzer to a new level of precision by analysing the chemical composition of dust particles rather than the gas surrounding the star.

“Most of the material within the disks is gas, but until now it has been difficult to study the gas composition in the regions where planets should form. Much more attention has been given to the solid dust particles, which are easier to observe.” – John Carr of the Naval Research Laboratory, Washington.

So far abundances of hydrogen cyanide, acetylene, carbon dioxide and water vapour have been discovered, allowing scientists to see whether these organic chemicals are enriched or lost during the violent period of planetary formation. Observations such as these highly accurate measurements allow us a chance to glimpse back in time to see what our protoplanetary solar system may have looked like, clearly a very exciting time for the quest to find the origins of life in our galaxy.

Source: NASA/JPL

March 13, 2008December 26, 2015 by Nicholos Wethington

Plans for a “Doomsday Ark” on the Moon are in the Works

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Let’s say something terrible happens to your computer, like it crashes or you drop it. All of those movies you bought online are toast, as is your address book and most of your work. It’s always a good idea to have a backup somewhere else, right?

Having a backup of your computer is handy, but having a backup of the entire progress of human civilization is even more practical. If a major catastrophic event like nuclear war or an asteroid strike wipes out most of the humans on the planet, it would be helpful for the survivors to have a record of all the accomplishments we’ve made in the past few thousands of years to help rebuild and repopulate the Earth.

The closest off-world place to store such a structure and ensure its safety would be the Moon. The construction of such a “doomsday ark” was presented last month by William Burrough and Jim Burke at a symposium on “Space Solutions to Earth’s Global Challenges” at the International Space University in Strasbourg, France.

There are already gene banks â€“ stores of plant seeds â€“ around the world, one of which is the Svalbard Global Seed Vault, which officially opened last month. But having a backup inside your computer doesn’t help if you drop it in a lake, so taking such an important operation off the Earth would make it that much more likely to survive any major catastrophes.

The ark would contain hard disks that store the genetic information of humans, plants and animals, as well as information on necessary or helpful processes for survival such as smelting metal, planting crops and building houses. Like the seed vaults, the ark could be expanded to include actual seeds, plants and frozen genetic material, which would aid in the re-population of these species given that a spacecraft could be launched to retrieve them.

After being constructed underneath the surface of the Moon to protect it from the radiation from the Sun and the extreme temperatures of the Moon’s surface, the vault could be set to automatically transmit the information to the Earth in case of disaster. Outposts containing a receiver and supplies necessary for survival would be installed across our planet to aid in rebuilding and the reception of information. The databank would transmit in a variety of different languages to ensure that the survivors could actually read the sent instructions.

To start, the ark would be tended by robots, but a future base on the Moon might allow it to be maintained and improved by human beings (an even better safeguard against humanity being wiped out).The scientists think it would be possible to place such an ark on the Moon before 2020. This basic archive would have a 30-year lifespan, and could be followed up with a more complete archive by the year 2035.

Source: Telegraph.co.uk

March 13, 2008December 26, 2015 by Fraser Cain

The Constantly Changing Vortex on Venus

ESA’s Venus Express has been constantly watching the huge swirling vortex of clouds around Venus’ southern pole. It’s a strange weather feature, morphing and changing shape within just a few days. And scientists, as you can probably imagine, are puzzled about what’s going on.

Venus’ south pole vortex is similar to a hurricane here on Earth. It measures 2,000 km (1,240 miles) across, and was discovered by the Mariner 10 flyby in 1974. A second, similar vortex was found at the planet’s north pole by the Pioneer Venus mission in 1979.

“Simply put, the enormous vortex is similar to what you might see in your bathtub once you have pulled out the plug” says Giuseppe Piccioni, co-Principal Investigator for the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on Venus Express, at IASF-INAF, Rome, Italy.

When Venus express observed the vortex in June 2006, it had a roughly hourglass-shape, similar to what Pioneer Venus saw in the north polar region. But with continued observations from Venus Express, scientists are seeing that the storm is much more fickle than they previously thought.

Over the course of just a single day, scientists watched the shape of the storm’s vortex change from a circle to a oval. It’s believed that atmospheric gases are flowing into the region from different directions at different altitudes. The shape of the vortex is a result of changes in temperature across different parts of the planet.

The actual vortex is created because atmospheric gases are heated by the Sun at the equator. They cool near the polar regions and sink down. The rotation of Venus deflects them sideways so they swirl together, like water going down the drain of a bathtub.

Original Source: ESA News Release

March 13, 2008December 29, 2015 by Fraser Cain

Carnival of Space #45

Another new host has taken control of the Carnival of Space. This week we’re over to the blog “Observations from Missy’s Window”. Learn about Von Neumann devices, the latest release of data from WMAP, and how, exactly, we know the Universe’s expansion is accelerating.

Click here to read the Carnival of Space #45

And if you’re interested in looking back, here’s an archive to all the past carnivals of space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, let me know if you can be a host, and I’ll schedule you into the calendar.

Finally, if you run a space-related blog, please post a link to the Carnival of Space. Help us get the word out.