Florence is the largest asteroid to pass Earth in a century

September 1, 2017 by  
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Though the American eclipse may have come and gone, the skies above Earth never cease to amaze with new interstellar events. Early this morning, according to NASA, Florence became the largest asteroid to approach our planet in over a century. The asteroid measures 2.7 miles (4.4 km) in diameter and passed by from the relative proximity of 4.4 million miles (7 million km) away from Earth, roughly 18 times the average distance between the Earth and the Moon. Although other asteroids have traveled closer to Earth in the past, none were as massive as Florence, the largest near-Earth asteroid ever tracked by NASA. Florence, like all asteroids in our solar system , formed out of the debris left behind after the formation of the planets and the sun . It was originally discovered by Schelte “Bobby” Bus at Siding Spring Observatory in Australia in 1981 and named after Florence Nightingale, the founder of modern nursing and pioneering statistician and social reformer. Florence’s trip near Earth, its closest since 1890, provided scientists with a unique opportunity to study the ancient asteroid. Related: Astrophysicist warns asteroid strike is not a matter of if, but when NASA researchers used deep space radar to study the size, shape, rotation, surface features, and determine the precise path of the asteroid. Amateur astronomers also observed the asteroid, which was relatively easy to spot since it reflects 20 percent of sunlight that reaches its surface, in contrast to only 12 percent reflection from the Moon . Scientists project that Florence will not come this close to Earth again until 2500. Via BBC Images via NASA (1) , (2)

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Florence is the largest asteroid to pass Earth in a century

First hints of water detected on Earth-sized TRAPPIST-1 planets

September 1, 2017 by  
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Water could be present on some of the Earth-sized planets orbiting the dwarf star TRAPPIST-1, according to work from an international group of astronomers. They utilized the NASA/ESA Hubble Space Telescope to estimate substantial amounts of water could be present in the outer planets, including three in the habitable zone. This boosts the possibility those planets are livable. Astronomer Vincent Bourrier of the Observatoire de l’Université de Genève led an international team that included scientists from NASA and MIT to attempt to determine if there’s water 40 light-years away on the seven Earth-sized planets orbiting TRAPPIST-1, a system which claims the biggest number of Earth-sized planets we’ve found to date. These researchers used the Space Telescope Imaging Spectograph on Hubble to scrutinize how much ultraviolet radiation the TRAPPIST-1 planets receive. Related: NASA discovers 7 Earth-sized planets outside our solar system Bourrier said ultraviolet starlight can break water vapor into oxygen and hydrogen . And those elements can escape as ultraviolet rays with more energy to heat a planet’s upper atmosphere. It’s possible for Hubble to detect escaped hydrogen gas, which can act as a “possible indicator of atmospheric water vapor,” according to the statement on the research. Some of the outer planets, including e, f, and g, could have water on their surfaces. During the last eight billion years, the inner planets of the TRAPPIST-1 system “could have lost more than 20 Earth-oceans-worth of water,” according to the statement. But the outer planets might have not lost that much, suggesting they could have retained water. While the hints are exciting, the scientists say we can’t draw any final conclusions quite yet. Bourrier said in the statement, “While our results suggest that the outer planets are the best candidates to search for water with the upcoming James Webb Space Telescope, they also highlight the need for theoretical studies and complementary observations at all wavelengths to determine the nature of the TRAPPIST-1 planets and their potential habitability.” Via Hubble Space Telescope Images via ESO/N.Bartmann/spaceengine.org and NASA/R. Hurt/T.Pyle

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First hints of water detected on Earth-sized TRAPPIST-1 planets

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