In what’s being called a “record-breaking exoplanet discovery” NASA announced today the detection of not one, not two, not three or four but seven exoplanets orbiting the ultra-cool dwarf star TRAPPIST-1, located just under 40 light-years away in the constellation Aquarius. (That’s astronomically very close, although still 235 trillion miles distant.) What’s more, these exoplanets aren’t bloated hot Jupiters or frigid Neptune-like worlds but rather dense, rocky planets similar in size to Earth…and at least three of them are well-positioned around their dim red star to permit liquid water to exist on their surfaces.
TRAPPIST-1 and its planets are like a miniature version of our inner Solar System; the star itself is only slightly larger than Jupiter with a mass about 8% of our Sun, and the planets B through H all have orbits smaller than the diameter of Mercury’s. Still, even an ultra-cool dwarf star has a habitable zone, and three of these planets lie within it. The others may very well also possess habitable regions on or inside them too.
“This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate in Washington, D.C. “Answering the question ‘are we alone’ is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal.”
The seven-planet system was confirmed through (and named for) the ground-based TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope as well as observations from NASA’s Spitzer Space Telescope.
“This is the most exciting result I have seen in the 14 years of Spitzer operations,” said Sean Carey, manager of NASA’s Spitzer Science Center at Caltech/IPAC in Pasadena. “Spitzer will follow up in the fall to further refine our understanding of these planets so that the James Webb Space Telescope can follow up. More observations of the system are sure to reveal more secrets.”
Like some giant beast’s great blue eye Saturn’s north polar vortex appears to glare up at Cassini’s wide-angle camera in this image, a color-composite made from raw images acquired in red, green, and blue visible light wavelengths on February 13, 2017.
It sounds like a surprise challenge posed by the “Dungeon Master” in a game of Dungeons & Dragons but this is sort of what happened on a cosmic scale on Feb. 6, 2017, when the 200-meter (656-foot) -wide asteroid 2017 BQ6 passed by Earth. Using the radar imaging capabilities of the giant 70-meter antenna at NASA’s DSN facility in Goldstone, CA, scientists got a good look at the object as it passed—and it does seem to resemble a tumbling gaming die!
“The radar images show relatively sharp corners, flat regions, concavities, and small bright spots that may be boulders,” said Lance Benner of NASA’s Jet Propulsion Laboratory in Pasadena, California, who leads the agency’s asteroid radar research program. “Asteroid 2017 BQ6 reminds me of the dice used when playing Dungeons and Dragons. It is certainly more angular than most near-Earth asteroids imaged by radar.”
Everything we’ve observed so far about the surface of Mars points to an ancient past that was warmer, wetter, and very possibly habitable for life as we know it. From the scars of enormous floods and vast branching river deltas that are etched into the Martian surface to the rounded pebbles of ancient stream beds to the chemical signatures of materials formed only in the presence of water, the evidence for Mars’ wet history seems overwhelming. But there’s one big question that still stymies scientists: what happened to all of Mars’ carbon dioxide?
Even though Mars’ atmosphere is 96% CO2 today, it is incredibly thin—only 1% as dense as Earth’s. It’s thought that Mars once had a much thicker atmosphere in its early history, but was there enough of the greenhouse gas even then to keep it warm enough (with a cooler young Sun) to maintain liquid water on its surface? According to a new analysis of data from NASA’s Curiosity rover, Mars just didn’t have enough carbon dioxide 3.5 billion years ago to provide enough warming to prevent water from freezing solid.
“We’ve been particularly struck with the absence of carbonate minerals in sedimentary rock the rover has examined,” said Thomas Bristow of NASA’s Ames Research Center. “It would be really hard to get liquid water even if there were a hundred times more carbon dioxide in the atmosphere than what the mineral evidence in the rock tells us.”
But with all the physical evidence pointing at liquid water—even without the CO2—could something else have been keeping Mars warm?
Read the full story from NASA here: NASA’s Curiosity Rover Sharpens Paradox of Ancient Mars
Launched on Sept. 8, 2016, NASA’s OSIRIS-REx spacecraft is heading out into the main asteroid belt beyond the orbit of Mars to meet up with the 1,600-foot-wide asteroid Bennu. Ultimately OSIRIS-REx will map and collect a sample of Bennu’s surface, returning it to Earth in 2023. But while it’s still traveling through near-Earth space in preparation for a gravity-assist flyby this September, mission scientists will take advantage of OSIRIS-REx’s position near L4 to look for any captured “Trojan” asteroids.
The European Southern Observatory has begun imaging the Sun for the first time, using its Atacama Large Millimeter/submillimeter Array (ALMA)—a suite of large dish-type telescopes located on a plateau 16,000 feet above sea level in the arid Chilean Andes. ALMA’s capabilities to observe in millimeter and submillimeter wavelengths allow imaging of the Sun’s dynamic chromosphere and the features within it, such as the center of a sunspot (above) that’s easily twice the size of Earth.
Read more here from ESO: ALMA Starts Observing the Sun