Ross gives a tour of the Spring Night Sky, including the constellations Boötes, Leo and Ursa Minor, as well as the visible planets this season. Learn about the planet Saturn, its rings and some tips on finding it for yourself.
It could be the Sahara or Egypt’s Western Desert, but this sand-covered crater is the latest image from Mars.
The picture was taken from US space agency Nasa’s Mars exploration rover, Opportunity, close to where the robotic unit spent the winter analysing soil and air samples. The picture shows the explorer’s deck and solar panels, tracks it had previously made and a crater that was created by an impact billions of years ago.
Opportunity has now spent 3,000 Martian days on Mars (eight and a half Earth years), and Nasa has consistently had a robot there for 15 years. Mars Pathfinder landed on 4 July 1997; Nasa’s Mars Global Surveyor orbiter reached the planet while Pathfinder was still active; and Global Surveyor overlapped the active missions of the Mars Odyssey orbiter and Opportunity. The latter two are both still in service.
Back in 2007, black spots were discovered on Mars that are so dark that nothing inside can be seen. Quite possibly, the spots are entrances to deep underground caves capable of protecting Martian life, were it to exist.
The unusual hole pictured above was found on the slopes of the giant Martian volcano Arsia Mons. The above image was captured three weeks ago by the HiRISE instrument onboard the Mars Reconnaissance Orbiter currently circling Mars.
The holes were originally identified on lower resolution images from the Mars Odyssey spacecraft, The above hole is about the size of a football field and is so deep that it is completely unilluminated by the Sun. Such holes and underground caves might be prime targets for future spacecraft, robots, and even the next generation of human interplanetary explorers.
Titan’s golden, smog-like atmosphere and complex layered hazes appear to Cassini as a luminous ring around the planet-sized moon. The world beneath that haze has become slightly less mysterious under the gaze of Cassini and its Huygens probe, but many new discoveries await.
Credit:NASA/JPL/Space Science Institute
Enceladus: A Tectonic Feast
The Cassini spacecraft has been studying Saturn and its moons since it entered orbit in 2004. This image, taken on Oct. 5, 2008, is a stunning mosaic of the geologically active Enceladus after a Cassini flyby.
Credit: NASA, ESA and E. Karkoschka (University of Arizona)
Saturn is ready for her close-up. This image, taken by the Hubble Space telescope in 2004, offers a stunning view of the planet’s rings. Saturn boasts 9 continuous main rings as well as three fragmentary arcs; they’re made mostly of ice with some dust and rock mixed in. In this image, the main body of the planet casts a dark shadow on the rings.
THEY look dark, but mysterious expanses on Mars are mainly made of glass forged in past volcanoes.
The dark regions make up more than 10 million square kilometres of the Martian northern lowlands, but their composition wasn’t clear. Past spectral measurements indicated that they are unlike dark regions found elsewhere on the Red Planet, which consist mainly of basalt.
Briony Horgan and Jim Bell of Arizona State University in Tempe analysed near-infrared spectra of the regions, gathered by the Mars Express orbiter. They found absorption bands characteristic of the iron in volcanic glass, a shiny substance similar to obsidian that forms when magma cools too fast for its minerals to crystallise (Geology, DOI: 10.1130/G32755.1).
The glass likely takes the form of sand-sized grains, as it does in glass-rich fields in Iceland. The spectra suggest the grains are coated with silica-rich “rinds”.
On Earth, such rinds coat volcanic glass weathered by water. How the glassy grains formed on Mars is unknown, but Horgan says magma from Martian volcanoes interacting with water ice and snow is a possibility. That would make these regions (pictured right) potential hotspots for alien life because they would have held chemical-rich water - a key ingredient for life.