Astrobiology Magazine 16 Apr 2018, 17:28 UTC In recent history, a very important achievement was the discovery, in 1995, of 51 Pegasi b, the first extrasolar planet ever found around a normal star other than the Sun. In a paper published in EPJ H, Davide Cenadelli from the Aosta Valley Astronomical Observatory (Italy) interviews Michel Mayor from Geneva Observatory (Switzerland) about his personal recollections of discovering this exoplanet. They discuss how the development of better telescopes made the discovery possible. They also delve into how this discovery contributed to shaping a new community of scholars pursuing this new field of research. In closing, they reflect upon the cultural importance that the 51 Pegasi b discovery had in terms of changing our view of the cosmos.
Astro Bob 16 Apr 2018, 16:56 UTC This weekend, powerful winds blasting across Lake Superior created monster waves that exploded like bombs when they struck the shore. My daughter Katherine and I spent some time along the lake, leaning into the wind and watching nature have its way on this watery planet. Astronomers are constantly on the lookout for planets orbiting within the habitable zones of their host suns. These are places at the right distance from a star where a rocky planet would be warmed enough for liquid water to pool on its surface. Water is quintessential to life on Earth, so if we’re going to start the search for alien life, a watery planet’s a good choice.
Starts With a Bang! 16 Apr 2018, 14:01 UTC The star TW Hydrae. an analogue of the Sun and other sun-like stars, in its very early stages already shows evidence of new planets forming at various radii in its protoplanetary disk. S. Andrews (Harvard-Smithsonian CfA); B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO)After generations of speculations, we’ve finally got the images that tell us the full story.Some 4.5 billion years ago, our Sun and Solar System were born from a collapsing cloud of gas, likely alongside many other stars.Artist’s impression of a young star surrounded by a protoplanetary disk. There are many unknown properties about protoplanetary disks around Sun-like stars, but observations are catching up. (ESO/L. Calçada)Over time, a protoplanetary disk forms, where imperfections will lead to young planets that eventually create full fledged solar systems.A large number of protoplanetary systems have been imaged, but the state-of-the-art infrared imager designed for exoplanet disk pictures is SPHERE, which routinely obtains resolutions of ~10", or less than 0.003 degrees per pixel. (SHINE (SpHere INfrared survey for Exoplanets) collaboration / Arthur Vigan)The details of how that work, however, have varied wildly depending on which stars we look at.
SPACE.com 16 Apr 2018, 13:42 UTC A gravitational wave detector that's 2.5 miles long isn't cool. You know what's cool? A 25-mile-long gravitational wave detector. That's the upshot of a series of talks given here Saturday (April 14) at the April meeting of the American Physical Society. The next generation of gravitational wave detectors will peer right up to the outer edge of the observable universe, looking for ripples in the very fabric of space-time, which Einstein predicted would occur when massive objects like black holes collide. But there are still some significant challenges standing in the way of their construction, presenters told the audience.
Scientific American 16 Apr 2018, 11:00 UTC Almost all space missions launched so far by our civilization have been based on chemical propulsion. The fundamental limitation here is easy to understand: a rocket is pushed forward by ejecting burnt fuel gases backwards through its exhaust. The characteristic composition and temperature of the burnt fuel set the exhaust speed to a typical value of a few kilometers per second. Momentum conservation implies that the terminal speed of the rocket is given by this exhaust speed times the natural logarithm of the ratio between the initial and final mass of the rocket.
In the Dark 16 Apr 2018, 10:59 UTC Just before Easter (and, perhaps more significantly, just before April Fool’s Day) a paper by van Dokkum et al. was published in Nature with the title A Galaxy Lacking Dark Matter. As is often the case with scientific publications presented in Nature, the press machine kicked into action and stories about this mysterious galaxy appeared in print and online all round the world. So what was the result?
AmericaSpace 15 Apr 2018, 16:33 UTC Had the cruelty of fate not intervened, almost a half-century ago, this month, the fifth and sixth humans ever to set foot on another world would twice have walked on the dusty surface of the Moon. Following their launch aboard Apollo 13, and a four-day voyage across 240,000 miles (370,000 km) of cislunar space, on 16 April 1970 Apollo 13 Commander Jim Lovell and Lunar Module Pilot (LMP) Fred Haise would have boarded the Lunar Module (LM) Aquarius and accomplished humanity’s third piloted landing on our closest celestial neighbor. If near-disaster had not radically altered their mission, Lovell and Haise would have performed two Extravehicular Activities (EVAs) at a place called Fra Mauro, becoming the first Apollo astronauts to explore a hilly upland lunar site. “It was driven by confidence in the LM capability and steerage,” Haise told the NASA Oral History Project of the site selection, years later, “but also, if you’re going to properly sample the Moon…you had to become more diverse in…where you went to get a proper sampling.”
All About Space 15 Apr 2018, 16:00 UTC It’s hot, at a searing average temperature of 460 degrees Celsius – some 410 degrees hotter than the muggiest deserts on Earth. Its atmosphere is thick with choking carbon dioxide, laced with poisonous sulphuric acid clouds which hang above a parched desert-like landscape, renewed by the angry eruptions of volcanoes. Without a shadow of a doubt Earth’s evil twin, Venus, with its additional high pressure environment – that has a crushing power 100 times that of Earth – is unfriendly for life. Sending astronauts onto a world that can cook, crush and choke in a few seconds flat and hoping for their survival is ambitious to say the least.
Astrobiology Magazine 15 Apr 2018, 16:00 UTC Step outside on a clear night, and you can be sure of something our ancestors could only imagine: Every star you see likely plays host to at least one planet. The worlds orbiting other stars are called “exoplanets,” and they come in a wide variety of sizes, from gas giants larger than Jupiter to small, rocky planets about as big around as Earth or Mars. They can be hot enough to boil metal or locked in deep freeze. They can orbit their stars so tightly that a “year” lasts only a few days; they can orbit two suns at once. Some exoplanets are sunless rogues, wandering through the galaxy in permanent darkness.