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On the 14th July 1965 NASA’s Mariner 4 flew past Mars and kicked off humankind’s exploration of the red planet with robotic spacecraft*. In the 43 years since that event, our knowledge of Mars has grown at an incredible rate. Not only do we now know a great deal about Mars’ fascinating past but we can get daily (sol-ly?) updates from a small flotilla of spacecraft, on the surface and orbiting the planet. From those early grainy monochrome images of the martian surface we have come all the way to snapping images of our own craft parachuting to the surface; to explore in situ and see much more too. Our missions have captured images from Mars that have shown us: landslides falling down cliffs, dust devils whipping across the martian plains and have generally opened our eyes to the desolate (but stunning) world with which we have become fascinated over the centuries.

For me though one of the best things about our exploration of Mars, aside from the science, is how the images have been able to convey the beauty of the red planet. Not only from a purely aesthetic viewpoint either. The images we see put the complex scientific information we receive into a human context. A high silica content in a region of soil may mean little to anyone but a specialist. But if we can look at an image and say: “that white patch there shows that this region might once have been home to a warm pool of standing water, perhaps even with a bubbling hydrothermal vent” then the whole scene jumps to life.

So it’s with this in mind that I’m posting this image above, one of the Mars Express spacecraft’s latest images. You can view the big version here, to get the full effect. It’s part of a region called Echus Chasma on Mars and has been shaped by all sorts of processes from volcanic events to water erosion. However my favourite quote about the image below, from the ESA news article about these new images, has to be this: “Gigantic water falls may have once plunged over these cliffs on to the valley floor. The original shoreline is still partially visible. The remarkably smooth valley floor was later flooded by basaltic lava.” The fact that we can make such an incredible comment about Mars, to me, shows just how far we’ve come from those early Mariner days.

*There is of course a grand history of observing Mars, with telescopes from Earth, that dates back many decades prior to this.

Image credits: Credits: ESA/ DLR/ FU Berlin (G. Neukum)

I’m always impressed by the images that come back from Mars Express’ High Resolution Stereo Camera (HRSC). This new one released a few days ago (below) is no exception. It shows a region called Hebes Chasma, a vast gauge into the martian surface around 8 kilometres deep! The incredible feature is located just above the main canyon on Mars, the impressive and truly staggering in size (3000km long!), Valles Marineris. Each pixel in the image corresponds to 15 metres on the martian surface.

Scientists studying the image believe it shows evidence of landslides, depositions and other hints of a terrain shaped by erosion, large-scale geological activity and water. In fact recently the spectrometer on-board Mars Express detected signs of water-bearing minerals around Hebes Chasma showing that there have clearly been, according to ESA, “significant quantities of water” there in the past. To see more images as well as the high-res versions visit the ESA page here. If you have got some 3D specs then have a look at the anaglyph below to see Hebes Chasma in perspective.

Also a quick mention to thank all the people who came to my Hubble talk in Torquay on the 20th. It was good to visit Torbay again and to see many faces from the Torbay Astronomical Society which I haven’t seen for a while. I’m going to be heading over to Belfast on Tuesday for a few days for the Royal Astronomical Society’s National Astronomy Meeting 2008. When I get a moment I will post about some of the fascinating discoveries and announcements that always come up at NAM. It seems I will be in good company!

Top image: Hebes Chasma from the HRSC on Mars Express
Bottom image: A 3D anaglyph of the Hebes Chasma region
Image credits: ESA/ DLR/ FU Berlin (G. Neukum)

There are a handful of very cool things going on in space over the next few days. Here’s my very quick run down of what not to miss.

The first event is happening in the wee small hours of tomorrow morning. The European Space Agency is launching the ATV, the Automated Transfer Vehicle, atop its Ariane 5 launcher. This is essentially a very large unmanned supply ship that is capable of flying to the International Space Station under its own power. It is going to be launched from the ESA launch site at Europe’s Spaceport in Kourou, French Guiana on Sunday morning at 04:03 GMT.

Once the ATV is at the station it will supply the ISS with drinking water, fuel for the station’s propulsion, food for the astronauts, clothing and spare parts for the new Columbus lab. It will also use its engine to boost the ISS into a higher orbit. Something that is very important to do as the ISS continually encounters the drag from the Earth’s atmosphere, causing it to slow and fall closer to Earth. You can read more about the ATV here and also watch the launch live here.

EDIT: The ATV has now successfully launched! You can try and see it too, albeit briefly, in the night sky (before it docks presumably) - more details at Heavens-Above.com

Above: An ESA Ariane 5 with the ATV inside, poised on the launchpad.
Credits: ESA - S. Corvaja 2008

The next Space Shuttle mission, STS-123, is set to lift-off from Cape Canaveral as well at 21:28 GMT on Tuesday 11th March. This is a night-time launch (by my recollection that hasn’t happened for a while) so should look very cool as the shuttle, Endeavour, rises into the inky black darkness. This will be the 25th flight to the ISS and Endeavour will be carrying a robotic system and the Japanese Kibo Logistics Module. You can watch the launch live on NASA TV and find out more about the Space Shuttle at the NASA page.

Above: The shuttle Endeavour lifting off on a previous 2007 mission.
Credit: NASA/John Kechele, Scott Haun, Tom Farrar.

The Cassini orbiter is going to be flying right over Enceladus’ surface on March 12th. Passing by only 50km above the icy moon’s surface we should see some truly incredible science come out of this flyby. Hopefully we will find out more about those jets! Cassini won’t be imaging though, at its closest appraoch, as it will be travelling far too fast not to take blurry pictures. But the pictures from before and after the approach should be amazing. You can get all the updates from the Cassini-Huygens website over at JPL when they are released.

Lastly then the Moon passes very close to the Pleiades cluster of stars on Wednesday (12th March); making for a nice early evening view through some bins or a small telescope. Visit the night sky page for more info.

After just over seventeen years in space the Ulysses space probe looks as if its mission is drawing to a close. According to the European Space Agency Ulysses is beginning to show the signs of age, after nearly two decades touring the Solar System in orbit around its main interest - the Sun. The spacecraft is in a somewhat peculiar six year orbit around the Sun which takes it at one extreme flying right out to Jupiter and at the other extreme whirling over the Sun’s polar regions.

Ulysses has scrutinized the Sun in great detail over its seventeen or so years, telling us about the solar wind (the stream of charged particles emanating from the Sun), the Sun’s powerful magnetic field as well as how the Sun’s chromosphere and corona interact. One of Ulysses’ most interesting finds was that the solar wind at the poles of the Sun is emerging much faster than at the equator (with speeds of 750km/s and 350km/s respectively); and that the polar winds dominate about 2/3 of the heliosphere (the vast ’shield’ around the Sun created by the solar wind). The probe, which was launched from the Space Shuttle’s cargo bay in 1990 has also studied Jupiter’s magnetic fields and the plasma environment around the giant planet.

So why is Ulysses dying after all these years? Well the probe itself is powered by the radioactive decay of a special isotope of plutonium. This decay slowly releases heat which the probe’s on-board technology converts into electricity. This in turn powers heaters, the science instruments and the communication antennae that are needed to send data back to Earth. However over time the radioactive isotope decay levels drop meaning that so to do the amounts of electricity produced.

This poses a problem for the craft because as it ventures out into space it needs its on-board heaters to keep the spacecraft at the right temperature. If they don’t and the craft’s temperature drops below 2°C then the probe’s fuel hydrazine (where have you heard that before) will freeze solid. It reminds me a bit of the lizards on David Attenborough’s incredible new BBC series ‘Life in Cold Blood’. They either need the Sun to warm them or find some heat of their own, otherwise they will freeze and die.

The scientists working with the Ulysses probe realised that if they didn’t do something the power levels would drop so much that the heaters and the science instruments would stop working - freezing the all important fuel. So in January they turned off the main transmitter that was sending data back to Earth in the hope that the re-routed power would go to the heaters and the science packages; keeping the hydrazine liquid. Unfortunately when they wanted to turn the transmitter back on to see if it had worked nothing happened. Now it seems Ulysses’ fuel will freeze as the probe cools in the vacuum of space to that crucial 2°C, bringing with it the end of an illustrious mission. Thankfully though there are many missions which are taking up Ulysses’ baton like SOHO, Stereo, Trace and Hinode. So solar science will be continuing into solar cycle 24, long after little Ulysses ends.

Above: An artist’s impression of the Ulysses probe
Credit: ESA