Solar System Super Snapshots
Here are some of the most fascinating new images coming from spacecraft out there on duty – but they didn’t just come in on their own. They are brought to you by highly intelligent and dedicated human beings: the navigators, instrument teams, deep space network engineers, flight controllers and scientists who gather and distribute the bountiful data manna from the heavens for the whole world to enjoy.
- Mars Rovers: Spirit and Opportunity are celebrating their 4th anniversary this month (see mission page). Latest images can be found on the press images page. Spirit ended the old year with a dazzling panorama from its winter nesting ground (see caption). Not to be outdone, the sibling rover Opportunity showed off its track record inside Victoria Crater (see press release).
Incidentally, if you heard that a large meteor is headed for Mars, JPL’s near-earth-object watchers have now ruled out an impact. See the press release from JPL.
- Saturn: The poles of Saturn are hot. This is the reverse of the pattern on Earth, and appears unrelated to the amount of sunlight hitting the pole, said a press release from Jet Propulsion Lab. Also unexplained is the hexagon-shaped feature over the north pole; see larger image at Planetary Photojournal and the movie.
- Titan: The Cassini spacecraft went lake-hunting over the south pole of Titan last month, wondering if it would find a similar lake-spotted landscape found at northern latitudes. Here is the result: only a couple of candidate lakes. Scientists are now wondering if the lakes migrate from one pole to the other for the Titanian winter.
Note: the colors are interpretations of data from the Cassini radar. Smooth areas are interpreted to be lakes, and are artificially colored blue in the image. Radar, of course, has no color.
Another radar image shows evidence of flowing liquid, probably runoff from methane storms. The image looks similar to the descent photos taken by Cassini’s ride-along Huygens Probe, which landed three years ago this month. Have you taken the wild ride with Huygens down to the surface?
- Epimetheus: A little moon of Saturn, just outside the main rings, has taken quite a beating, as revealed in a Cassini image. One whole face seems bashed in by a giant impact that left a central peak on rebound. The moonlet, about 72 miles in diameter, shows a variety of compositional materials and some geological processing, such as slumping of dark material.
- Ring moons: Saturn’s two little ringsweeper moons, Daphnis and Pan, were revealed in a single image taken December 1. Pan is the larger one, inside the Encke Gap; Daphnis, about 1/4 as large as Pan, plows through the center of the Keeler Gap. If you look closely you can see how the gravitational tug of the moons distorts the surrounding ring material. A movie from 2005 shows the action; see also the narrated version.
- Mars Odyssey: The infrared orbiter Mars Odyssey has such a huge collection of images, it would be unfair to pick just one, but last June’s shot of flood-scoured terrain is certainly a keeper. The thermal imager on Odyssey brings out much more information from the data, as seen in this sample thermal overlay.
One of the more intriguing images from Odyssey last fall was the discovery of deep cave pits. The press release says some of them are almost 800 feet across. It was by measuring the temperature differences between day and night that scientists inferred these are deep holes, not impact craters. They were found on the flanks of a large volcano.
- The Outer Limits: Remember the never-say-die Voyagers? They are still on duty at the farthest reaches of our solar system. Their most recent achievement was to pass the heliosheath, where the solar wind impacts the interstellar medium. From the two separate data points, scientists determined that our interstellar bubble is squashed (see artist conception), perhaps due to the interstellar wind from nearby stars.
- Solar Poles: Ulysses, the solar polar mission, is in the middle of its third north-pole pass over our sun. It’s arriving just in time to watch the fireworks of the new solar cycle begin; keep abreast of solar activity at SpaceWeather.com.
- Venus: The European Space Agency’s Venus Express has been orbiting our sister world since April 2006, and now has a collection of science images and artworks on its multimedia page.
- True Blue: Rosetta has a ways to go on its mission to land on a comet in 2014, but it snapped this beautiful picture of home last November when just passing by.
- Mars in HD: For sheer dazzlement, it’s hard to surpass the wonderful set of high-resolution images coming from the Mars Reconnaissance Orbiter, affectionately known as “Mr. O”. The HiRise Camera website, managed by the University of Arizona, can keep you occupied for hours or days. Bookmark the link to the latest images for a weekly treat. This magnificent camera can image things as small as a card table from orbit.
The silver medal for orbital images goes to the European Space Agency’s Mars Express. Its 3D oblique images are the next best thing to being a Martian. Browse at length and put on a happy face.
- Encores: Let your eyes be the spacecraft: Space.com listed comets that can be seen from Earth: Tuttle and Holmes. And check out the postcard from Jupiter: a dazzling montage of Jupiter and erupting Io (10/15/2007) from last year’s encounter made Astronomy Picture of the Day for January 8.
We are just 2 days away from Messenger’s first pass of Mercury (see Johns Hopkins Applied Physics Lab press release). This should provide the first images of the innermost planet in over 30 years, since Mariner 10 gave mankind the first close-ups during three passes in 1974-1975. Messenger will make three passes over Mercury in 2008-2009, finally settling into orbit in March, 2011. Watch the Science Images page for the latest.
What’s coming? The Phoenix lander arrives at the Martian north polar cap on May 25. Mars Science Laboratory, the next-generation super-rover, is being assembled now for launch in fall 2009. Dawn is on the way to asteroids Vesta (2011) and Ceres (2015). New Horizons is cruising beyond Jupiter for a 2015 encounter with Pluto. And Cassini, after a daredevil fly-through of the Enceladus geysers on March 12, climbs into high-inclination orbit to celebrate the end of its prime mission on June 30 with stunning views high over Saturn. But don’t mourn the end of a great ride; next day, July 1, Cassini begins its first multi-year extended mission – with perhaps another to follow, if all systems keep operating as well as they have since the 2004 arrival at Saturn. Check out Cassini’s video collection.
In short, there is plenty of spirit and opportunity in space flight to inspire a young generation of explorers to join the veterans. There will be puzzles galore to solve and exotic places to visit for the first time.
Once in awhile you have to lift up your eyes from the battles over evolution on earth and just take time to marvel at outer space. We get to see things almost daily that earlier astronomers could only dream about. Keep the dream alive – with a good hand-hold on reality.
As you enjoy the alien worlds, keep in mind how lifeless and stark they are compared to the Earth. A recent article on LiveScience said that our planet is right on the edge of habitability: “If Earth had been slightly smaller and less massive, life might never have gained a foothold.” Were it not for just the right geosphere, atmosphere, and orbital distance, there would be no biosphere. Human civilization, with all its ups and downs for over 6,000 years, has had a remarkably safe ride through the battleground of space (03/07/2007). Of all people who have ever lived, we should be the ones to thank God the most for a privileged planet that permits – and promotes – both habitability and scientific discovery.