¶SOFIA finds water on our nearest neighbor. NASA’s infrared-telescope-on-a-plane Sofia has detected water for the first time on the sunlit side of the Moon (paper), indicating that water, a valuable space resource, isn’t only available in shadowed and frigid lunar craters. Concentrations of 100-412 parts per million were detected, “roughly equivalent to a 12-ounce bottle of water – trapped in a cubic meter of soil spread across the lunar surface … [on the other hand,] the Sahara desert has 100 times [this] amount of water.” Upcoming missions to study lunar water include Lunar IceCube and Lunar Flashlight, which we discussed in Issue 84. We’ll also again link to Ice Prospecting: Your Guide to Getting Rich on the Moon. |
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¶All good things. In roughly 5 billion years, our local star will have converted enough of its hydrogen supply into helium that its core will no longer be in hydrostatic equilibrium and will start to collapse, increasing its internal density and temperature until helium and then heavier elements start to fuse. This in turn will cause the energy output of the Sun to surge, increasing its luminosity thousands of times and causing the outer atmosphere to expand 200x, out to ~1AU and consuming our rocky relic of a planet. Our Sun will have become a red giant. Roughly a billion years later, it will be a (very) slowly cooling white dwarf, 100x smaller than its current size, in the middle of an attractive, expanding “planetary” nebula (whose shape will be determined by the orbits of Jupiter and Saturn). Phil Plait has a good review of white dwarfs and planetary nebulae 📺. For the first time, an exoplanet has been found orbiting such a white dwarf, indicating that at least some planets can survive the deaths of their parent stars (paper). Picture the bizarre sight of a planet the size of Jupiter awkwardly orbiting a superdense object the size of Earth. This newly discovered gas giant likely formed further out, survived its star’s red giant phase, and then later migrated inwards. Related: Detecting life on rocky worlds orbiting white dwarfs may be easier than around other stars because white dwarfs are dimmer and don’t overwhelm our spectrographic sensors—JWST might even be able to do this (paper). |
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¶100 and counting. With the successful launch of Starlink-14, SpaceX completed its 100th successful mission (highlight video 📺). While that many missions over the past twelve years is an achievement in its own right, more impressive is that this milestone came on their 19th launch of 2020, meaning that almost 20% of their total launch count has happened in just the last 10 months (with upwards of 10 more launches, minus some likely scrubs, scheduled for the last two months of the year). The company also announced a partnership with Microsoft to provide connectivity for Azure mobile data center units—ruggedized modular datacenter-in-a-container solutions that are great for all sorts of applications… as long as they are defense-related. The upcoming week will likely contain an overdue update on Starship’s design evolution, and potentially a second 3-Raptor static fire of Starship SN8—this time from its header tanks, which were recently added as part of the first nose cone to be attached to a Starship prototype since last September’s Mk1. |
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¶TAG complete. Here’s a video of OSIRIS-REx’s 6 second touch-and-go sample collection 📺 on an object the size of the Empire State building, 350 million km away. Visual inspection has confirmed that plenty of material was collected—at least 60 grams, and likely closer to a kilogram—but unfortunately some of the material seems to be preventing a mylar flap on the sample head from fully closing, so precious grains are being lost due to inertia whenever the TAGARM is moved. The mission team is now planning to stow the head quickly, with as few motions as possible. The craft is coasting away from Bennu at 40 cm/s, which doesn’t sound like much, but it’s well over the asteroid’s 19 cm/s escape velocity—you could trip into interplanetary space from this thing. Scott Manley has a good review of how the sampling operation went 📺. Especially interesting: it looks like the TAGARM penetrated almost half a meter into Bennu—it has a very soft, extremely crumbly surface. This seems relevant if we ever need to deflect it. |
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¶Papers. - InSight’s seismometer was sensitive enough to detect Phobos during a solar eclipse (paper), likely due to the ground briefly cooling and causing a tilt of the sensor by a very tiny amount— “Imagine a 5- franc coin; now, push two silver atoms under one edge. That’s the incline we’re talking about: 10-8.” This data will help to determine Phobos’s orbit more precisely. (Related: InSight’s mole is now out of sight!)
- Another exoplanet first: new research presents evidence of the first exoplanet in another galaxy—a Saturn-sized exoplanet in the M51 Whirlpool Galaxy, 23 million light years away. This detection was only possible because the binary system containing the planet consists of a neutron star or black hole that is actively consuming its companion, making the system incredibly X-ray bright, with a luminosity ~1 million times greater than the sun. And then something eclipsed it.
- A new analysis finds that neutron star mergers alone cannot explain the abundance of heavy elements (such as gold) in the galaxy. This paper presents a periodic table of elements annotated with their likely astrophysical sources and suggests that a type of supernova called a magnetorotational supernovae may be responsible for much of the Earth’s heavier elements. Science Alert has a good summary.
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¶News in brief. Astronauts Chris Cassidy, Anatoly Ivanishin, and Ivan Vagner returned from the ISS in a Soyuz capsule, leaving 3 crewmembers aboard—on Nov. 2nd, every person under the age of 20 will have lived only in a world in which humans have been continuously living in space; Crew-1 is now scheduled to lift off NET November 14 and will carry four astronauts to bolster the ISS’s minimal crew; Russia launched a Soyuz with a next-generation GLONASS-K navigation satellite aboard; meanwhile, along with multiple firings, two Roscosmos officials were arrested on charges of embezzlement related to corruption that has plagued the construction at Vostochny Cosmodrome, the future launch site of the Angara rocket; the PROSWIFT space weather bill was signed into law, assigning weather observation, research, and forecasting duties to specific government departments (NASA, NOAA, & NSF among others); Blue Origin’s BE-3 engines are moving into production; and, US-based ABL Space systems is currently testing their integrated RS-1 upper stage, putting them on track for a 2021 launch, while Launcher completed a test firing campaign for their E-2 3D printed copper engine. |
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