The Five-hundred-meter Aperture Spherical Telescope (FAST) is nestled within a natural basin in China’s remote and mountainous southwestern Guizhou province. Nicknamed Tianyan, or the Eye of Heaven, the new radio telescope is seen in this photograph taken near the start of its testing phase of operations on September 25. Designed with an active surface for pointing and focusing, its enormous dish antenna is constructed with 4,450 individual triangular-shaped panels. The 500 meter physical diameter of the dish makes FAST the largest filled, single dish radio telescope on planet Earth. FAST will explore the Universe at radio frequencies, detecting emission from hydrogen gas in the Milky Way and distant galaxies, finding faint galactic and extragalactic pulsars, and searching for potential radio signals from extraterrestrials.
What’s happening in the Statue of Liberty nebula? Bright stars and interesting molecules are forming and being liberated. The complex nebula resides in the star forming region called RCW 57. This image showcases dense knots of dark interstellar dust, bright stars that have formed in the past few million years, fields of glowing hydrogen gas ionized by these stars, and great loops of gas expelled by dying stars. A detailed study of NGC 3576, also known as NGC 3582 and NGC 3584, uncovered at least 33 massive stars in the end stages of formation, and the clear presence of the complex carbon molecules known as polycyclic aromatic hydrocarbons (PAHs). PAHs are thought to be created in the cooling gas of star forming regions, and their development in the Sun’s formation nebula five billion years ago may have been an important step in the development of life on Earth. The featured image was taken at the Cerro Tololo Inter-American Observatory in Chile.
What mysteries might be solved by peering into this crystal ball? In this case, the ball is actually a moon of Jupiter, the crystals are ice, and the moon is not only dirty but cracked beyond repair. Nevertheless, speculation is rampant that oceans exist under Europa‘s fractured ice-plains that could support life. This speculation was bolstered again this week by released images from the Hubble Space Telescope indicating that plumes of water vapor sometimes emanate from the ice-crusted moon — plumes that might bring microscopic sea life to the surface. Europa, roughly the size of Earth’s Moon, is pictured here in natural color as photographed in 1996 by the now-defunct Jupiter-orbiting Galileo spacecraft. Future observations by Hubble and planned missions such as the James Webb Space Telescope later this decade and a Europa flyby mission in the 2020s may further humanity’s understanding not only of Europa and the early Solar System but also of the possibility that life exists elsewhere in the universe.
This image of Saturn could not have been taken from Earth. No Earth based picture could possibly view the night side of Saturn and the corresponding shadow cast across Saturn’s rings. Since Earth is much closer to the Sun than Saturn, only the day side of the ringed planet is visible from the Earth. In fact, this image mosaic was taken earlier this year by the robotic Cassini spacecraft now orbiting Saturn, just before filming a 44-hour video of Saturn rotating. The beautiful rings of Saturn are seen in full expanse, while cloud details are visible including the polar hexagon surrounding the north pole. The Cassini mission is now in its final year as the spacecraft is scheduled to be programmed to dive into Saturn’s atmosphere next September.
On September 18, the setting Sun illuminated both sides of the steep brick and steel canyon otherwise known as Jasper Avenue in downtown Edmonton, Alberta, Canada, planet Earth. The Stonehenge-like alignment is captured from the middle of the road in this daring snapshot. In Edmonton streets are laid out on a grid almost oriented along the cardinal directions, so aligned Edmonton sunsets (and sunrises) occur along the nearly east-west streets twice a year, close to the Equinox. In fact, at today’s Equinox, the Sun crosses the celestial equator at 1421 UT and on this day the Sun will rise due east and set due west, bringing approximately equal hours of day and night to denizens of planet Earth. The September Equinox marks the astronomical beginning of Fall in the north and Spring in the southern hemisphere.
After sunset this gorgeous full moon rose over Brno city in the Czech Republic on July 20, 2016. The panoramic image was made during a celebration of the 47th anniversary of the Apollo 11 lunar landing. A series of exposures captures the yellow hued lunar disk against the fading colors of twilight, with the 14th century Spilberk castle illuminated in the foreground. Of course, tonight’s full moon is called the Harvest Moon. The closest full moon to the northern hemisphere’s autumnal equinox, its traditional name has long been celebrated in story and song. Tonight’s full lunar phase also coincides with a subtle, penumbral lunar eclipse, the Moon passing only through the Earth’s diffuse, outer shadow.
A wide, looping orbit brought Juno close to Jupiter on August 27. As the spacecraft swung around the giant planet’s poles JunoCam acquired these premier direct polar views, a change from the usual nearly equatorial perspective of outbound spacecraft and the telescopes of planet Earth. The sunlit side of Jupiter’s north polar region (left) was imaged about 125,000 kilometers from the cloud tops, two hours before Juno’s closest approach. An hour after close approach the south polar region was captured from 94,500 kilometers away. Strikingly different from the alternating light-colored zones and darker belts girdling more familiar equatorial regions, the polar region clouds appear more convoluted and mottled by many clockwise and counterclockwise rotating storm systems. Another 35 close orbital flybys are planned during the Juno mission.
Many spiral galaxies have bars across their centers. Even our own Milky Way Galaxy is thought to have a modest central bar. Prominently barred spiral galaxy NGC 1672, featured here, was captured in spectacular detail in an image taken by the orbiting Hubble Space Telescope. Visible are dark filamentary dust lanes, young clusters of bright blue stars, red emission nebulas of glowing hydrogen gas, a long bright bar of stars across the center, and a bright active nucleus that likely houses a supermassive black hole. Light takes about 60 million years to reach us from NGC 1672, which spans about 75,000 light years across. NGC 1672, which appears toward the constellation of the Dolphinfish (Dorado), is being studied to find out how a spiral bar contributes to star formation in a galaxy’s central regions.
A little spacecraft that was presumed lost has now been found. In 2014, the Philae lander slowly descended from its parent Rosetta spacecraft to the nucleus of Comet C67/P Churyumov-Gerasimenko. At the surface, after a harpoon malfunction, the lander bounced softly twice and eventually sent back images from an unknown location. Earlier this month, though, Rosetta swooped low enough to spot its cub. The meter-sized Philae is seen on the far right of the main image, with inset images showing both a zoom out and a zoom in. At the end of this month, Rosetta itself will be directed to land on 67P, but Rosetta’s landing will be harder and, although taking unique images and data, will bring the mission to an end.
How much of planet Earth is made of water? Very little, actually. Although oceans of water cover about 70 percent of Earth’s surface, these oceans are shallow compared to the Earth’s radius. The featured illustration shows what would happen if all of the water on or near the surface of the Earth were bunched up into a ball. The radius of this ball would be only about 700 kilometers, less than half the radius of the Earth’s Moon, but slightly larger than Saturn’s moon Rhea which, like many moons in our outer Solar System, is mostly water ice. How even this much water came to be on the Earth and whether any significant amount is trapped far beneath Earth‘s surface remain topics of research.