Alnitak, Alnilam, and Mintaka, are the bright bluish stars from east to west (lower right to upper left) along the diagonal in this cosmic vista. Otherwise known as the Belt of Orion, these three blue supergiant stars are hotter and much more massive than the Sun. They lie from 800 to 1,500 light-years away, born of Orion’s well-studied interstellar clouds. In fact, clouds of gas and dust adrift in this region have some surprisingly familiar shapes, including the dark Horsehead Nebula and Flame Nebula near Alnitak at the lower right. The famous Orion Nebula itself is off the right edge of this colorful starfield. This well-framed, 2-panel telescopic mosaic spans about 4 degrees on the sky.
Nothing like it has ever been seen before. The unusual space rock ‘Oumuamua is so intriguing mainly because it is the first asteroid ever detected from outside our Solar System — although likely many more are to follow given modern computer-driven sky monitoring. Therefore humanity’s telescopes — of nearly every variety — have put ‘Oumuamua into their observing schedule to help better understand this unusual interstellar visitor. Pictured is an artist’s illustration of what ‘Oumuamua might look like up close. ‘Oumuamua is also intriguing, however, because it has unexpected parallels to Rama, a famous fictional interstellar spaceship created by the late science fiction writer Arthur C. Clarke. Like Rama, ‘Oumuamua is unusually elongated, should be made of strong material to avoid breaking apart, is only passing through our Solar System, and passed unusually close to the Sun for something gravitationally unbound. Unlike a visiting spaceship, though, ‘Oumuamua’s trajectory, speed, color, and even probability of detection are consistent with it forming naturally around a normal star many millions of years ago, being expelled after gravitationally encountering a normal planet, and subsequently orbiting in our Galaxy alone. Even given ‘Oumuamua‘s likely conventional origin, perhaps humanity can hold hope that one day we will have the technology to engineer ‘Oumuamua — or another Solar System interloper — into an interstellar Rama of our own.
Yes, but have you ever taken a selfie on Mars? The Curiosity rover on Mars has. This selfie was compiled from many smaller images — which is why the mechanical arm holding the camera is not visible. (Although its shadow is!) Taken in mid-2015, the featured image shows not only the adventurous rover, but dark layered rocks, the light colored peak of Mount Sharp, and the rusting red sand that pervades Mars. If you look closely, you can even see that a small rock is stuck into one of Curiosity’s aging wheels. Now nearing the end of 2017, Curiosity continues to explore the layers of sedimentary rocks it has discovered on Vera Rubin Ridge in order to better understand, generally, the ancient geologic history of Mars and, specifically, why these types of rocks exist there.
Young stars themselves are clearing out their nursery in NGC 7822. Within the nebula, bright edges and complex dust sculptures dominate this detailed skyscape taken in infrared light by NASA’s Wide Field Infrared Survey Explorer (WISE) satellite. NGC 7822 lies at the edge of a giant molecular cloud toward the northern constellation Cepheus, a glowing star forming region that lies about 3,000 light-years away. The atomic emission of light by the nebula’s gas is powered by energetic radiation from the hot stars, whose powerful winds and light also sculpt and erode the denser pillar shapes. Stars could still be forming inside the pillars by gravitational collapse, but as the pillars are eroded away, any forming stars will ultimately be cut off from their reservoir of star stuff. This field spans around 40 light-years at the estimated distance of NGC 7822.
Friday, an old Moon smiled for early morning risers. Its waning sunlit crescent is captured in this atmospheric scene from clear skies near Bursa, Turkey, planet Earth. In the subtle twilight hues nearby celestial lights are Jupiter (top) and Venus shining close to the eastern horizon. But today, Saturday, the Moon will be new and early next week its waxing crescent will follow the setting Sun as it sinks in the west. Then, a young Moon’s smile will join Saturn and Mercury in early evening skies.
Sometimes, the sky may seem to smile over much of planet Earth. On this day in 2008, visible the world over, was an unusual superposition of our Moon and the planets Venus and Jupiter. Pictures taken at the right time show a crescent Moon that appears to be a smile when paired with the planetary conjunction of seemingly nearby Jupiter and Venus. Pictured here is the scene as it appeared from Mt. Wilson Observatory overlooking Los Angeles, California, USA after sunset on 2008 November 30. Highest in the sky and farthest in the distance is the planet Jupiter. Significantly closer and visible to Jupiter‘s lower left is Venus, appearing through Earth’s atmospheric clouds as unusually blue. On the far right, above the horizon, is our Moon, in a waxing crescent phase. Thin clouds illuminated by the Moon appear unusually orange. Sprawling across the bottom of the image are the hills of Los Angeles, many covered by a thin haze, while LA skyscrapers are visible on the far left. Hours after the taking of this image, the Moon approached the distant duo, briefly eclipsed Venus, and then moved on. This week, another conjunction of Venus and Jupiter is occurring and is visible to much of planet Earth to the east just before sunrise.
The Moon is normally seen in subtle shades of grey. But small, measurable color differences have been greatly exaggerated in this mosaic of high-resolution images captured near the Moon’s full phase, to construct a multicolored, central moonscape. The different colors are recognized to correspond to real differences in the mineral makeup of the lunar surface. Blue hues reveal titanium rich areas while more orange and purple colors show regions relatively poor in titanium and iron. The intriguing Sea of Vapors, or Mare Vaporum, is below center in the frame with the sweeping arc of the lunar Montes Apenninus (Apennine Mountains) above it. The dark floor of 83 kilometer diameter Archimedes crater within the Sea of Rains, or Mare Imbrium, is toward the top left. Near the gap at the top of the Apennine’s arc is the Apollo 15 landing site. Calibrated by rock samples returned by the Apollo missions, similar multicolor images from spacecraft have been used to explore the Moon’s global surface composition.