The opening to a possible Martian cave stands out in this picture.

New images from Mars reveal football field-sized openings in the planet’s surface that likely lead to caves. Seven entrances to subterranean caves range from about 330 to 820 feet across, and there is absolutely nothing visible inside the holes, indicating that they are very deep. Perhaps one day robots will be able to explore the caves, revealing their now-hidden contents.

• Space.com on exploring the caves.
• The Planetary Society highlights pictures of the cave openings.
• Home page of the Home page for the Mars Reconnaissance Orbiter.
• Astrobiology Magazine talks about the caves' potential for harboring life.

This new image of Altair shows unprecedented detail. Credit: Ming Zhao, University of Michigan

For the first time, researchers have taken a picture of surface of Altair, a star like our own Sun. Even to the largest telescopes, stars look like mere points of light, but a new technique by the Center for High Angular Resolution Astronomy allows us to see detail on this distant star. And a strange star it is – orbiting so fast that it’s distorted, wider at its equator than at its poles.

• The National Science Foundation news release on the Altair picture.
• Solstation gives background on Altair.
• Home page of the Center for High Angular Resolution Astronomy.

SOFIA is an airliner modified to carry an infrared telescope.

NASA’s new Stratospheric Observatory for Infrared Astronomy (SOFIA) is a highly modified 747 airliner that carries a 45,000-pound infrared telescope system. SOFIA’s purpose is to fly above the water vapor in the Earth’s atmosphere that impedes infrared light, allowing its telescope to make powerful infrared observations. NASA recently commemorated the 80th anniversary of famed aviator Charles Lindbergh’s historic transatlantic flight by bestowing the name Clipper Lindbergh on the flying observatory.

• SOFIA completes its first test flight.
• SOFIA is dedicated in honor of Charles Lindbergh.

Hubble is staring into the galaxy M81, a shining spiral galaxy rife with star formation, for clues to how stars are born in galaxies outside our own. M81 is a great place to study this since it’s both a spiral galaxy like our own Milky Way and it’s close enough to allow us to distinguish individual stars. We can look at M81 and compare its star formation to what we know about stars in our own galaxy.

The icy, tiny object Eris helped demote Pluto from a planet to a dwarf planet. Eris, three times farther from the Sun than Pluto, was discovered in 2005 and is a member of the Kuiper Belt – a ring made up of small, icy bodies that are occasionally knocked out of their orbits and become comets. Eris, as it turns out, is also larger than Pluto, based on observations of Eris’ moon by Hubble and other observatories.

Jupiter is redecorating. The gas giant planet’s atmospheric patterns are in the process of changing, with entire bands of its distinctive surface colors morphing over just a few months. Other atmospheric features are also swiftly changing before Hubble’s eyes.

• Hubble Photographs Grand Design Spiral Galaxy M81
• Astronomers Measure Mass of Largest Dwarf Planet
• Hubble Catches Jupiter Changing Its Stripes

A ring of dark matter apparently formed in the collision of two galaxy clusters.

What happens when astronomers go on the hunt for dark matter with the Hubble Space Telescope? They find some unusual configurations.

Recently astronomers reported that observations with the Advanced Camera for Surveys suggested that a ring of the mysterious dark matter exists in a cluster of galaxies. This had never been seen before, and the surprised researchers thought maybe something was wrong with the data analysis. After scrutiny, it appeared a collision of two galaxy clusters shaped dark matter into a ring, like ripples in a pond after a stone is thrown in.

• HubbleSite news release on the dark matter ring.

A globular cluster with multiple stellar populations.

Globular clusters are tightly packed groups of hundreds of thousands to millions of stars. Based on observations of their stars, it seems that the clusters formed when the universe was young, and that the stars within them formed simultaneously. New observations with the Hubble Space Telescope suggest at least one globular cluster has had several episodes of star formation, billions of years ago. All of the stars were born within 200 million years, very early in the life of the 12.5-billion-year-old cluster, but at distinct periods.

• HubbleSite news release on the globular cluster.

The Martian landscape as seen by Viking I.

NASA is looking into health concerns for astronauts on long journeys, such as a potential Mars trip. A journey to Mars would take 20 to 30 years, meaning the crew would have to be prepared for serious medical crises. Just asking questions of Earth on such a trip could take half an hour or more for the message to travel, so astronauts will have to be ready to handle such situations on their own. A host of other health issues require rules and policies to be established in advance to prevent problems during long journeys or even stays on Earth’s Moon.

• Science@NASA on the health hazards of Mars.
• Space.com on dealing with death during a Martian trip.
• Psychiatry Online on the mental health of potential Mars-mission astronauts.
• San Francisco Chronicle on the physical and mental hazards of a Mars trip.

China plans to land an astronaut on the Moon in 15 years.

China plans to launch its first lunar probe this year and expects to land an astronaut on the Moon within 15 years. This year’s probe will provide 3-D images of Moon, survey the lunar landscape, study lunar microwaves and estimate the thickness of Moon’s soil. Other missions will follow, including a soft landing – one designed to avoid damage – in 2012 and return of lunar samples by 2017.

• Space.com reports on China's first lunar probe.
• The BBC on China's Moon goals.
• Space Today on China's rockets.