NASA’s Curiosity rover has drilled down into Mars to collect samples, and it’s revealed that just under the dusty red surface, the Red Planet is actually a greyish blue.
The drilling happened at a site called Telegraph Peak, right up in a region called Pahrump Hills, where Curiosity has been working for the past five months. It’s been drilling into the rocky surface to get some idea of how and when Mars evolved from a wet environment to the dry and dusty one we see today, and in the process has discovered that the dusty red top layer is made up of completely different stuff than the actual planet itself.
"The universe has really never made things in ones. The Earth is special and everything else is different? No, we’ve got seven other planets. The sun? No, the sun is one of those dots in the night sky. The Milky Way? No, it’s one of a hundred billion galaxies. And the universe—maybe it’s countless other universes." - Neil deGrasse Tyson
Jupiter’s moon Callisto is not the largest moon in the solar system, or even the largest of Jupiter’s natural satellites. But it does rank highest in one category: it is the most heavily cratered body in our solar system.
Callisto’s surface is about as evenly blemished as you could expect it to be from the random impacts it has received over the eons. Made up of equal parts of rock and ice, it’s surface captures the history of the violent past of the solar system. The outermost of Jupiter’s four Galilean satellites, it is nearly the same size as the planet Mercury, though it has only about one-third the mass of the speedy inner planet.
Callisto orbits Jupiter at a distance of nearly 3 million kilometers (1.8 million miles), considerably farther away from the planet than the other Galilean moons. That relative isolation is one of the reasons for the golf ball-like appearance of the moon. At that distance, Jupiter’s strong gravity exerts less force on Callisto than on the other large moons. Io, Europa and Ganymede pay for their proximity to Jupiter with geological processes like volcanism, plate tectonics and other resurfacing events. Callisto’s surface hasn’t had any such recent rejuvenation treatments, and it carries scars from the early solar system, dating back some four billion years.
This is the only complete full-color view of Callisto obtained by the Galileo spacecraft, which studied Jupiter and its moons from 1995 to 2003.
The star cluster Pismis 24 lies in the core of the large emission nebula NGC 6357 that extends one degree on the sky in the direction of the Scorpius constellation. Part of the nebula is ionised by the youngest (bluest) heavy stars in Pismis 24. The intense ultraviolet radiation from the blazing stars heats the gas surrounding the cluster and creates a bubble in NGC 6357. The presence of these surrounding gas clouds makes probing into the region even harder.
One of the top candidates for the title of “Milky Way stellar heavyweight champion” was, until now, Pismis 24-1, a bright young star that lies in the core of the small open star cluster Pismis 24 (the bright stars in the Hubble image) about 8,000 light-years away from Earth. Pismis 24-1 was thought to have an incredibly large mass of 200 to 300 solar masses. New NASA/ESA Hubble measurements of the star, have, however, resolved Pismis 24-1 into two separate stars, and, in doing so, have “halved” its mass to around 100 solar masses.