New analysis of data taken by the Cassini mission during its encounter with Jupiter in 2000 reveal that exceptionally clear atmospheric ‘hotspots’ effectively ride up and down in the Jovian skies as they are formed by what’s known as a Rossby wave – a phenomenon familiar to us here on Earth. The authors of the [...]

There is nothing particularly scientific about this image, but it is remarkably evocative. The Curiosity rover on Mars took a self-portrait of its primary camera masthead using another camera (the rather charmingly named “Mars Hand Lens Imager” or MAHLI)  mounted on its robotic arm on Sept 7th 2012. In part the image was made to [...]

When the Sun is eclipsed by the Moon this Sunday, for many observers across much of the world it will be temporarily replaced by a beautiful ring of fire – a brilliant annulus of stellar plasma just peeking out around the dark lunar disk. This doesn’t always happen, partial solar eclipses merely trim away a [...]

It seems that the Saturnian system just keeps on giving when it comes to amazing imagery. Of course it helps to have a $3 billion space mission in place like Cassini to record everything going on. From Saturn The Movie, to The Austere Beauty Of Other Worlds, and Raw Footage From An Alien World, I’ve [...]

If there is one thing our universe makes a lot of, it is water. This isn’t an immediately obvious property based solely on the universal inventory of stuff. Hydrogen utterly dominates normal matter throughout the cosmos, and despite some 13 billion years of stellar nuclear fusion only a small number of these primordial protons have [...]

Understanding the structure, dynamics, and chemistry of planetary atmospheres is key to exoplanetary science. It’s sobering to realize that as of now it is still an enormous challenge to model even the atmospheres of planets in our own solar system. Despite great advances, a variety of trickery has to be employed to simulate a swirling [...]

The first exoplanet discovered around a normal star in 1995 was anything but normal in comparison to our own solar system. 55 Pegasi b is a gas giant world orbiting every 4.23 days – placing it some eight times closer  to its stellar parent than the planet Mercury is around the Sun. At least half [...]

Let’s get something clear right away, Mars has lots of water on and close to its surface. Over the years we’ve seen an increasing number of measurements and discoveries that indicate very significant reservoirs of martian water. The catch, and there is a big one, is that this water is frozen. It’s not surprising; Mars [...]

Another quick refurbishment from the archives, this one about the Juno mission to Jupiter. With any luck in a few hours Juno will launch and be on its way, arriving at Jupiter in 2016. This post was written while the spacecraft was still snug in its clean room.     The next post will be [...]

THE WOODLANDS, Texas—Planetary scientists, usually an affable lot, are plenty riled up at the moment. The field is bristling at cutbacks, proposed last month by the Obama administration, to planetary science and especially to NASA’s program of robotic Mars explorers. Researchers gathered here for the annual Lunar and Planetary Science Conference have taken turns railing [...]

NASA just released its presidential budget request for 2013 and, as expected, the space agency’s planetary science program takes a big hit. The budget document (summary pdf) is merely the first volley in an often drawn-out exchange between the White House and Congress, but still sets the general direction for the space program. Although the [...]

AUSTIN, Texas—Astrophysicists have a funny attitude toward magnetic fields. You might say they feel both repelled and attracted. Gravitation is assumed to rule the cosmos, so models typically neglect magnetism, which for most researchers is just as well, because the theory of magnetism has a forbidding reputation. The basic equations are simple enough, solving them [...]

On March 17, after a roundabout, nearly seven-year journey, NASA’s MESSENGER probe became the first spacecraft to orbit Mercury, the closest planet to the sun. MESSENGER, which stands for MErcury Surface, Space ENvironment, GEochemistry, and Ranging, launched in 2004 on an inward-spiraling path through the inner solar system that covered nearly eight billion kilometers and [...]

Electromagnetic pulses from far-flung celestial objects can provide a sort of scale with which to gauge the mass of the planets, according to a new study. The technique relies on the regularity of ultrashort blasts of radiation from pulsars, which result from the collapse of a massive star to an extremely dense and rapidly spinning [...]

In a pair of flybys by a robotic explorer last year, planetary scientists began to unravel some of the mysteries of Mercury, a planet that is difficult to study from Earth and that had not been visited by a spacecraft since the 1970s. Today brings the third such near approach to the planet by the [...]