Human travelers to Mars face many challenges. One of the biggest unknowns is exactly what effect radiation from the Sun and cosmic rays will have on the human body for the 1,000 days a journey to Mars might take. If the risk turns out to be high, there are methods that could cut down the amount of radiation humans might receive on the journey. One method could be to build parts of the spacecraft out of plastic, which absorbs radiation 20% better than aluminum; liquid hydrogen, which would be needed for fuel absorbs cosmic rays 2.5 times better.

Dr. Hayley Bignall, an astronomer from the Joint Institute for Very Long Baseline Interferometry in Europe (JIVE), believes that interstellar clouds of gas and dust can serve as a natural lens to magnify distant objects better than any human-built telescope. Every galaxy, including our own Milky Way has a cloud of particles around it, which naturally clump together by gravity. Radiation from a distant object passing through these clouds (light, radio waves, etc) can be focused to reveal details.

The latest image released from the European Space Agency's Mars Express spacecraft is of Kasei Vallis; one of the largest outflow channels on Mars. The image was taken using the spacecraft's High Resolution Stereo Camera (HRSC) while it was cruising above the planet at an altitude of 272 km. It's believed that the outflow channel was carved by glaciers, or the bursting of subterranean lakes which were dammed by glaciers. Operators had a difficult time building a true-colour image from this photograph because of all the dust and haze in the atmosphere at the time.

Construction of the European Space Agency's Herschel Space Observatory is well underway, and engineers recently completed a significant part of what will become the largest mirror on a space telescope. The 3.5 metre primary mirror was built from silicon carbide, which reduces its mass by a factor of 5 from using traditional materials. The mirror will next be machined to reduce its mass even more and then coated with a reflective surface. Herschel is due to launch in February 2007, and will cover the far infrared and sub-millimetre waveband.

NASA has postponed the test of its X-43 prototype because of a problem with the aircraft's rudder. The 4-metre X-43 is affixed to the front of a Pegasus rocket which will be launched from a B-52 aircraft. Once the X-43 is accelerated to Mach 7 on the rocket, it will use its scramjet engine to fly under its own power. Unlike traditional rocket engines, scramjets don't need to carry oxygen to burn rocket fuel. The aircraft uses its speed to compress air from the atmosphere and use this to burn fuel. This allows a scramjet to save weight and carry more cargo. It's unknown when the repairs to the prototype will be completed.

If you have clear skies on the early evening of Monday, February 23, get outside and look to the West for a beautiful sight. You can't miss Venus and a crescent Moon blazing in the Western sky, right beside each other. The Moon will only have 15% of its surface illuminated, and Venus is so bright right now, that the two objects may look equally bright. You might even be able to see the reflected light of the Earth shining on the Moon, revealing its complete circular shape. Don't miss it.

NASA's Opportunity rover dug into the Martian soil today, to get a better idea of the composition of the minerals beneath the top layer. The maneuver was done by locking five of the rover's six wheels and then turning the sixth in place to scoop soil like a waterwheel. After Opportunity completed the dig, scientists were able to confirm that the rover had dug down approximately 8-10 centimetres into the Martian soil. Its next operation will be to examine the unearthed dirt with its array of instruments.

According to researcher Ralph Lorenz, Saturn's moon Titan could help teach scientists about how oceans and weather work on the Earth. Titan is thought to have oceans of liquid methane, but they are created under a completely different environment from our own familiar oceans. When Cassini and the Huygens probe arrive at the Saturn system in 2004, they will begin gathering data about Titan and its oceans and weather, and help answer questions like: how deep are its oceans? do they form steep cliffs or shallow beaches? and what effect does Saturn's huge gravity have?

Here's a new desktop wallpaper (1024x768 resolution) of the latest rock visited by NASA's rover Spirit, which scientists have dubbed "White Boat". The rock stood out to scientists because of its unusual shape and colour compared to the other darker rocks around it. Spirit's next task will be to make a "mega drive" 25 metres towards a nearby crater called "Bonneville". On the other side of Mars, Opportunity completed a 9 metre drive, and is getting set to trench out a spot of soil rich in hematite. Both rovers should send back a mountain of scientific data for the folks on Earth to analyze.

Since Earth and Mars were probably formed much the same way; through the accretion of rocky material from the inner solar system, they should have roughly the same amount of water, but Mars is pretty much bone dry compared to the Earth. So what happened to make it so dry? Some scientists believe that Mars used to have the same amount of water as Earth, but it evaporated into space. Others believe that the Red Planet never had much water in the first place; that it started out as a collection of dry materials from the asteroid belt.

A Boeing-built Titan IV-B rocket lifted off from Florida's Cape Canaveral on Saturday afternoon, carrying a Defense Support Program satellite into orbit. The rocket lifted off at 1850 UTC (1:50 pm EST), and the satellite was placed into a geosynchronous orbit seven hours later. The DSP-22 satellite is equipped with sensitive heat detection instruments, designed to spot the heat of launching missiles. This constellation of military satellites first launched in the 1970s, and the final one is due to go up in early 2005.

An international team of astronomers have found what could be the most distant galaxy ever discovered. Located 13 billion light-years away, it's being seen when the Universe was only 750 million years old. The object was found by combining the power of the Hubble Space Telescope and the W.M. Keck telescope; they also used the natural gravitational lensing effect of a relatively nearby galaxy, which focused the light of the more distant galaxy. This galaxy is small - only 2,000 light-years across - but it's forming stars at a furious rate.

The European Space Agency has picked a special image taken by Envisat for Valentine's Day. The radar image is of a land feature called Sebkha Te-n-Dghamcha, which is a large depression in the Sahara Desert. The region once contained a lake, but it evaporated, and now all that remains are shallow ponds of salty water.

A new theory from University of Arizona researcher Xiaohui Fan predicts that the supermassive black holes which form the core of most galaxies were created only 700 million years after the Big Bang, when the Universe was only 6% of its current age. Fan used data from the Sloan Digital Sky Survey to analyze the light of distant quasars, as far away as 13 billion light-years. He found that they contained light elements like hydrogen and helium, but also heavier elements like carbon and iron, which shouldn't have formed so early. But they could be explained if these black holes formed so early.

NASA and the European Space Agency have demonstrated that their spacecraft can talk to each other. In a recent test, the ESA's Mars Express orbiter transferred data and commands to NASA's Spirit rover. The commands for the rover were transferred from Spirit's control centre at JPL to the ESA's operations centre in Darmstadt Germany and then transmitted to Mars Express, which connected to Spirit on the surface of Mars. Spirit then transmitted back to Mars Express, and the communications went in reverse. The two agencies planned this demonstration as part of their ongoing work to cooperate in space.

An instrument on board NASA's Spirit rover has detected warm air thermals rising off the surface of Mars; the first time this has been seen on the Red Planet. Thermals on Earth work to create wind, so by analyzing the temperature and speed of these thermals, it will better help scientists understand wind dynamics on Mars. On the other side of the planet, Opportunity has found unusual blueberry-shaped formations in the soil, and scientists are studying them to understand the soil's development.

Astronomers from the Harvard-Smithsonian Center for Astrophysics have found a diamond in space, and it's big? really big. The object, technically known as BPM 37093, is a crystallized white dwarf star approximately 4,000 km across. The astronomers call it a diamond, because it's made up of crystallized carbon surrounded by a thin layer of hydrogen and helium gasses. It's believed that this is the final outcome for many stars, including our own Sun. In five billion years our Sun will become a white dwarf and two billion years after that the carbon should crystallize to form a gigantic diamond.

Just in time for Valentine's Day, here's a 1024x768 wallpaper of nebula NGC 7129 taken by the Spitzer Space Telescope - it looks like a pink rosebud. Previous images of this nebula taken by optical telescopes just look like a few stars surrounded by a haze of gas. By viewing the nebula in infrared light, astronomers are able to see which stars have swirling rings of material around them that will eventually form planets.

Officials announced today that they have given up search for the Beagle 2 lander, which was supposed to have landed on Mars on December 25, 2003. The spacecraft stopped communicating when it entered the planet's atmosphere, and months of searching with several Mars orbiters and Earth-based radio telescopes have failed to turn up any signal. The ESA and UK Science Minister Lord Sainsbury said that an inquiry will begin shortly to look into the failure of the lander.