This false colour composite image of Titan, Saturn's largest moon, was taken by Cassini on April 16 during its recent flyby. It was created by combining two infrared images of Titan with a visible light image. The green represents places where Cassini could see down to the surface, red indicates areas high in Titan's atmosphere, and blue shows the moon's outer edge. The images were taken when Cassini was approximately 160,000 km (100,000 miles) away.

One of the big hazards for astronauts living on the Moon is going to be the dust; it gets everywhere, and is very dangerous to breathe. Lunar dust is similar to silica dust on Earth, which can cause silicosis, a disease that damages the lungs. Martian dust could be even more dangerous because it is a strong oxidizer - it could actually burn your skin if it touched. Future missions will need to control lunar and martian dust from getting inside spacecraft and habitats, and NASA is working on potential solutions.

New observations from the Solar and Heliospheric Observatory (SOHO) has helped solar astronomers trace the source of the Sun's solar wind. The solar wind is a constant stream of protons, alpha particles, heavy ions and electrons flowing from the Sun. The solar wind had been seen streaming from various regions on the Sun, but scientists have now been able to work out the structure of funnel-shaped magnetic fields that carry material from below the surface of the Sun, and eject it into space.

This image shows nebula N214, a large region of dust and gas located in the neighbouring Large Magellanic Cloud galaxy. The image was taken using the European Southern Observatory's 3.5m New Technology telescope (NTT) located at La Silla in Chile. The central, brightest spot in the nebula isn't a star, but a cluster of stars that add up to about 80 solar masses. The large blob of gas at the top of the nebula probably contains a massive star, probably 40 times our Sun, which is putting out 200,000 times as much energy.

The European Space Agency's Mars Express spacecraft took this unusual photograph of the Aureum Chaos region on Mars. It's located at the eastern part of the Valles Marineris, near a large impact crater called Aram Chaos. The history of this region is very complex. It was probably filled with sediment and then large areas collapsed due to the removal of ice, water or magma; various flat-topped mesas remained.

Japanese astronomers have used the 8.2m Subaru Telescope to get detailed images of the envelope of gas and dust surrounding a very young star in M17. This envelope extends in a symmetrical butterfly shape about 150 times the size of our Solar System. This image hints at the process of how matter streams into the protostellar disc during early formation of a new star.

When NASA's Genesis smashed into the desert last year, mission controllers and scientists feared the worst for the spacecraft's fragile particle collectors. However, after having examined them carefully, it appears that plenty of useful science will be possible with the collected material. The four solar wind collectors, in an instrument called the concentrator are in excellent condition and should help scientists understand how the Solar System formed.

There's a number in the Universe which we humans call alpha - or the fine structure constant. It shows up in almost every mathematical formula dealing with magnetism and electricity. The very speed of light depends on it. If the value for alpha was even a little bit different, the Universe as we know it wouldn't exist - you, me and everyone on Earth wouldn't be here. Some physicists have recently reported that the value for alpha has been slowly changing since the Big Bang. Others, including Jeffrey Newman from the Lawrence Berkeley National Laboratory have good evidence that alpha has remained unchanged for at least 7 billion years.

There's going to be a partial lunar eclipse on Sunday, April 24; unfortunately, the Moon will only pass through the faint penumbral shadow, and only dim slightly. Most observers would be hard-pressed to tell the difference. The eclipse gets going at 0955 UT (5:55 am EDT) and ends about 2 hours later. Observers in the Americas should be able to see the eclipse, with the best view for folks in the West.

The planets in our Solar System formed more than 4.6 billion years ago from cloud of dust and gas that collapsed under gravity. Scientists have speculated that this cloud lasted anywhere from 1 to 10 million years, but new research has pegged that period at 2 million years. An international team of researchers studied a variety of meteorites that had formed just before the planets. One group, called calcium aluminum-rich inclusions are known to have formed early in the solar nebula, and others, called chondrules, formed right at the end - 2 million years later.

Researchers from the University of Colorado at Boulder have uncovered a group of bacteria living in an extreme environment in Yellowstone National Park in Wyoming. The hardy microbes were discovered living inside rocks near geothermal vents, and are regularly subjected to an acidic environment with high levels of metals and silicates and very high temperatures. These microbes can end up as fossils, so scientists can see how they've changed over time, and they can learn additional signs to look for life on Mars.

NASA's Spitzer Space Telescope has discovered an enormous asteroid belt orbiting another star, containing 25 times as much material as the belt in our Solar System. If we had an asteroid belt this thick, it would light up the night sky in a bright band. Once confirmed, this will be the first asteroid belt found orbiting a star similar to our own Sun. Another possibility is that Spitzer is seeing a Pluto-sized comet which has been orbiting the star for many years and has left a bright trail of particles.

NASA's Lunar Prospector hinted at the possibility that there are pockets of water ice in permanently shadowed craters at the Moon's poles. These reservoirs of water would be and invaluable supply of drinking water and air for astronauts, as well as the raw material for propellants. Scientists just need to confirm that it's there. NASA will be sending a new spacecraft, the Lunar Reconnaissance Orbiter, in 2008. It'll have four separate instruments capable of detecting water. So, we might know the answer soon.

Physicists with MIT have reported the discovery of a new state of matter - a perfect liquid - which was probably present in the earliest moments after the Big Bang. The team smashed atoms together in the Relativistic Heavy Ion Collider, creating a plasma that lasted for only an instant. The particles in the plasma have the same properties as a liquid; they cling together and move in a pattern, but they would flow much more easily than water if they could be poured.

The biggest mass extinction in the Earth's history happened approximately 250 million years ago. During the "Great Dying", more than 90% of creatures in the ocean, and 75% of life on land went extinct. What caused the extinction is still up for debate, but a researcher from the University of Washington thinks that low levels of oxygen in the atmosphere sure didn't help. Oxygen went down to 12% (currently it's 21%), and this made standing at sea level the same as being atop a 5,300 metre mountain (17,000 feet).

Now firmly in orbit, the European Space Agency's SMART-1 is seeking out a spot at the Moon's north pole that could be bathed in constant sunlight. Scientists are predicting that there's a spot, a few square kilometres in size across that is constantly heated by the sun, and would be the perfect spot for a lunar base. Finding the area is difficult, though, because we don't get a good view from Earth, and the shadows in this region are very long and can obscure the details.

NASA's Opportunity rover has lost the ability to steer its right-front wheel, making it more difficult for controllers to maneuver it around on the surface of Mars. The problem happened on April 13 (sol 433) when the rover was executing a turn - its wheel stuck at a slight angle. The rover has continued to travel since the problem happened, and can make observations, but it's more difficult to make precise movements.

The Chandra X-Ray Observatory spent 150 hours examining supernova remnant G21.5-0.9, revealing a beautiful ghostly shell. The shell is created by the shockwave of particles ejected by the supernova explosion as they slam into material that was sloughed off earlier by the star. This shockwave heats the surrounding material to millions of degrees causing it to blaze in the X-ray spectrum visible to Chandra. The star that produced this explosion was probably 10 times larger than the Sun.

Since its formation billions of years ago, Mars has never been a perfectly spherical planet. Even now, the planet has the huge Tharsis Bulge on one side of the planet, where volcanic activity raised up vast region several kilometres above the surrounding plain. These instabilities have caused the planet to wobble on its orbit, obscuring its original orientation. A Canadian researcher has traced 5 impact craters which came from a single object that broke up as it struck the planet, defining the planet's original poles and equator.

Researchers from UC Berkeley have looked into the past to confirm that a fundamental aspect of the Universe - the fine structure constant, or alpha - has remain unchanged for at least 7 billion years. This constant shows up in many formulae dealing with electricity and magnetism, and helps describe how radiation is emitted by atoms. This conflicts with a recent announcement from Australian researchers that described a change in alpha over time.

Let's say you're browsing around the comic book store and happened to notice a perfect copy of Action Comics #1 on the rack mixed in with the current stuff. It's in mint condition, untouched since it was first printed almost 70 years ago. Now imagine the same situation... except with stars. Anna Frebel is a PhD student at the Research School of Astronomy & Astrophysics at the Australian National University. She's working with a team of astronomers who have found the oldest star ever seen - possibly untouched since shortly after the Big Bang.

Oh, yeah. There's a Moon - but it's going to do some great tricks as it leads the way to the M44, shows us an Apollo landing site, offers a variety of observing challenges, occults Jupiter and Eta Virginis, and even has a penumbral eclipse! This week provides an opportunity to view bright double stars, enjoy some "colors" and even catch a "falling star". So get out those binoculars and telescopes, because...

Here's what's up!

NASA's DART mission, which launched on Friday to test automated docking techniques, was prematurely shut down on Saturday when the spacecraft ran out of fuel. DART launched perfectly on board a Pegasus XL rocket and reached within 90 meters of its target, an inactive satellite already in orbit. It was supposed to make several close approaches to the satellite, but it didn't even have enough propellant for one pass. Mission controllers aborted the mission and fired its deorbit rockets to put it into a decaying orbit where it will burn up. An investigation team has been assigned to figure out what went wrong.

Scientists have been watching a huge iceberg called B-15A, after it split away from Antarctica almost 5 years ago. After drifting along the coast of the continent, it finally smashed into the 70 km Drygalski ice tongue, breaking off a large chunk. The ice tongue is such a well known feature of Antarctica that it appears on many maps (they'll need to be revised). B-15A, on the other hand, appears totally unaffected by the collision, and will continue to grind away at the tongue.

The newest residents of the International Space Station arrived at their destination on Saturday, as their Soyuz TMA-6 capsule docked automatically. Hatches between the spacecraft and station were opened a few hours later, and the three crew members joined the two men of Expedition 10 on board the station. Commander Sergei Krikalev and astronaut John Phillips will remain on the station until October 2005, while ESA Astronaut Roberto Vittori will return in about a week with Leroy Chiao and Salizhan Sharipov.

Here's a relief. Instead of being painfully stretched (aka spaghettified) by the immense tidal forces around a black hole, you'd probably just be roasted by the intense heat. Professor Andrew Hamilton at the University of Colorado predicts that only the smallest black holes would actually stretch you out like this. All the larger, supermassive black holes are already choking on enough material, that their surrounding environment is a superhot plasma heated to millions of degrees and blasting out intense radiation.

Michael Griffin addressed NASA employees on Thursday, when he became the 11th Administrator for the space agency. In his address, Griffin said he would focus on getting the shuttles ready to return to flight, and continue to fulfill the Vision for Space Exploration, which sees astronauts returning to the Moon and eventually continuing on to Mars in the coming decades. Griffin was nominated by President Bush on March 14, and was confirmed by the Senate on April 13.

The 11th crew to man the International Space Station blasted off from the Baikonur Cosmodrome on Thursday. The Soyuz TMA capsule carrying Cosmonaut Sergei Krikalev, Astronaut John Phillips, and European Space Agency Astronaut Roberto Vittori of Italy reached orbit a few minutes after launch. Krikalev and Phillips will replace the current crew, while Vittori will only remain on the station for a week and then return with Expedition 10. The Soyuz will dock on Saturday.

NASA's Cassini spacecraft captured this beautiful image of Saturn's moon Enceladus perched just above the giant planet's rings. Enceladus is 505 km (314 miles) across, and the photo was taken when Cassini was just below the ring plane. Saturn's A, B, and C rings are also visible in the photograph.

When astronomers discovered that the planets around Upsilon Andromedae had very strange orbits, they weren't sure what could have caused it. Researchers from Berkeley and Northwestern have developed a simulation that shows how an additional planet could have given the other planets the orbital kick they needed to explain their current eccentricities. If a similar planet had passed through our own Solar System early on, all our planets could be in wildly different orbits around the Sun.

While Spirit and Opportunity could still be scouring the Red Planet in a few years, they'll be joined by a new partner: the Mars Science Laboratory. Schedule for launch in 2009, this mission will deliver a rover three times as large as the current rovers to the surface of Mars. It will have a suite of scientific instruments including the ChemCam: a powerful laser that will allow it to vapourize and analyze rock from 10 metres (33 feet away). And since it'll be powered by a radioactive powerplant, it won't need to rely on feeble solar power for energy.

NASA's Cassini spacecraft is scheduled to make its closest ever flyby of Titan on April 16. The spacecraft will get within 1,025 km (640 miles) of the moon's surface, and will get some extremely high resolution images. This image shows the regions that Cassini will photograph and analyze with its instruments.

Astronomers from the Australian National University think they've found one of the earliest stars to have formed in the Universe. It's called HE 1327-2326, and it has the lowest levels of iron ever found in any star. Heavier elements like iron only form inside stars, so HE 1327-2326 could have formed before successive generations of stars had seeded the Universe. This star was observed using the Japanese Subaru 8-m telescope, and found to be twice as iron poor as the previous record holder.

When it comes to using advanced technology, NASA sometimes faces a self-defeating loop: they can't take the risk of flying new technology in space unless it's already flown successfully in space. The New Millennium Program circumvents that loop by testing and validating the performance of leading-edge technologies in space so that they can be used in future operational science missions. Examples of upcoming New Millennium missions include advanced solar arrays, fault-tolerant high speed computers, a Nanosat (microsatellite) constellation, and perhaps, a solar sail.

Astronomers searching for potentially destructive Earth-crossing asteroids have revised the scale they use to communicate the risk of impact to the public. The Torino scale, which still goes from 0 (no chance of impact) to 10 (collision is certain) has the same classifications, but it's been rewritten to give the public a better idea of the risks associated with different space rocks. Instead of "meriting concern", lower risk objects now "merit attention by astronomers", explaining that astronomers will be making further observations.

Most objects in the Solar System have been resurfaced by collisions with asteroids, smaller rocks and comets. But Sedna, on the other hand, has spent its lifetime in the remote reaches of the Solar System, and probably hasn't had many impacts at all. It's only been weathered by cosmic rays and solar ultraviolet radiation. Astronomers think that Sedna started out icy, like Pluto and Charon, but was then baked for millennia, until the ice was transformed into a complex hydrocarbon similar to asphalt.

Are you liking astronomy but feeling unsure about how to take that first step? Have a friend showing a spark of interest in stars and you want to get them a small present? Look no further than Robin Scagell's book, Stargazing with a Telescope. In a concise, well pictured presentation, he describes the myriad of optical aids that bring our night time visage much closer and provides ready tricks for sizing up the relative benefits. Reading this book makes that first step less likely to be a mis-step.

The Milky Way - like all spiral galaxies - swings gracefully around a central super-massive black hole (SMBH). Astronomers have known for some time that a "fairy ring" of youthful blue-hot stars dance within a few light-years of its event horizon, but such stars should be very old and display expansive low-temperature red giant envelopes. Could there be a "fountain of youth" in the center of the Milky Way Galaxy?

Today NASA has 55 active mission control teams monitoring ongoing spacecraft and station missions - 13 associated with missions extended beyond original planning. Soon there may be seven less. By October of this year, we could be turning a deaf ear to data collected by one of the most successful NASA programs of all times. For even as Voyager 1 and 2 are poised to enter the interstellar realm, budget-minders in our nation's capital may have already sealed the fate on a pair of craft that could provide important information about our solar system - and beyond - for the next 15 years.

It's back. Yes, the Moon will figure prominently in this week's night sky, but it will put on a grand show as we have several occultations and a grazing event in store. We'll have plenty of opportunities to view new lunar features and catch a "shooting star" as we enter a very unusual meteoroid stream. So grab your telescopes and binoculars, because...

Here's what's up!

Since the beginning of astronomical observation, science has been viewing light on a curve. In a galaxy filled with thousands of eclipsing binary stars, we've refined our skills by measuring the brightness or intensity of so-called variable star as a function of time. The result is known as a "light curve". Through this type of study, we've discovered size, distance and orbital speed of stellar bodies and refined our ability to detect planetary bodies orbiting distant suns. Here on Earth, most of the time it's impossible for us to resolve such small objects even with the most powerful of telescopes, because their size is less than one pixel in the detector. But new research should let us determine the shape of an object... like a ringed planet, or an orbiting alien space station.