2019
July
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The Very Large Telescope checks out the Alpha Centauri system

The closest star system to our Sun (4.37 light-years away) consists of two Sun-like stars (Alpha Centauri A and B) and the red dwarf Proxima Centauri. Astronomers already discovered a rocky planet orbiting Proxima Centauri. But what about the binary Alpha Centauri system? A new instrument named NEAR and developed by the “Breakthrough Watch” Initiative and the European Southern Observatory (ESO) is set to find out.

NEAR (Near Earths in the AlphaCen Region) is, above all, a so-called thermal infrared coronagraph. The instrument blocks out most of the light received from a target star and at the same time is optimized not to measure any light reflected from a possible planet, but instead the thermal radiation (heat) emitted by the planet. Thus, NEAR can also determine whether liquid water might exist on the surface of the planet – and thus whether the planet is in that star system’s habitable zone.

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Into space with Blue Origin: test seating in New Shepard

In 2019, the private space travel company Blue Origin is still planning on being the first private organization to bring humans above the Karman line to an altitude of 100 kilometers (62 miles) and thus officially into space. The company founded by Jeff Bezos (Amazon) is setting its hopes on the “New Shepard,” a suborbital rocket with a passenger and cargo capsule that is launched and also landed by remote control – and is also reusable. It’s not yet clear how expensive the flights will be, but its competitor Virgin Galactic offers something similar for $250,000 (but not with “real” rockets and not above the Karman line).

I was able to try out the capsule at the Re:MARS Conference hosted by Amazon in Las Vegas – without actually launching into space, unfortunately. The capsule has room for six passengers. Each traveler has his or her own large window (considerably larger than an airplane window). Space in the capsule is naturally somewhat tight. The reclined seats are designed so that you sit with your knees bent. Nevertheless, I felt very comfortable. That is also not an unimportant detail, because ultimately, you’ll have to be able to endure up to 4.7g in that seat (almost five times the acceleration due to gravity).

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How does a radio telescope work? A visit to the Very Large Array

Every – okay, almost every – object in the universe emits light. When astronomers talk about light, however, they’re not only talking about the small portion of the entire electromagnetic spectrum that humans can see, i.e., the optical range, but instead they’re talking about all of it: radio waves, infrared, visible light, UV light, X-rays, gamma radiation (listed here in order of decreasing wavelength). Physicists would call this “electromagnetic radiation,” but “light” also fits very well, because, in the end, the same laws always apply for reception. Resolution, focal length, etc., it doesn’t matter if you are using a giant dish or a telescope, the terms always have the same meaning.

A radio telescope, as should be obvious, detects radio “light” from celestial objects. This is interesting, because radio waves are barely affected by dust and other obstacles, which is different, for example, from optical light (which cannot pass through dust) or infrared (which cannot pass through the Earth’s atmosphere). The ideal, of course, is to observe an unknown object in all wavelengths. All-wavelength observations is actually the big trend right now in astronomy; the technical term for it is “Multi-Messenger Astronomy.”

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Three exocomets discovered in orbit around Beta Pictoris

NASA’s satellite TESS is actually supposed to be searching for exoplanets. To do this, TESS records light curves of stars, that is, the change in brightness of a star over time. If something happens in a certain rhythm in these light curves, then there must be something there covering the star repeatedly – something like a planet. Or maybe a comet! TESS has apparently just discovered three of these in orbit around the nearby star Beta Pictoris.

Sebastian Zieba, a graduate student on a team led by Konstanze Zwintz at the Institute for Astrophysics and Particle Physics at the University of Innsbruck, discovered the signal of the exocomets when he analyzed the TESS light curve from Beta Pictoris in March of this year. “The data showed a significant decrease in the intensity of the star’s light. These fluctuations due to the darkening by an object in the star’s orbit can clearly be associated with a comet,” says Zieba, explaining the discovery published in the international journal Astronomy and Astrophysics.

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Where the geysers on Neptune’s moon, Triton, come from

Triton is a strange moon. It is the only one of the large moons of our Solar System that rotates the wrong way about its planet – Neptune, the eighth and outermost planet. That’s also why it’s assumed that Triton is a Kuiper belt object, similar to Pluto, that was captured by Neptune. On first look, Triton appears very hostile to life – at temperatures close to 0 Kelvin, the atmosphere, which consists of nitrogen, methane, and carbon monoxide, is almost completely frozen, and thus it is very thin; Earth’s atmosphere is 70,000 times thicker.

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Fly to Mars with NASA – on board the next Mars rover

Right now, not only can you send a postcard into space, but you can also send your name to Mars – on board NASA’s Mars 2020 rover. All you need to need is enter your name and e-mail address at go.nasa.gov/Mars2020Pass. Your name will then be etched onto a microchip that is mounted on the rover. Your name will be arranged on a line that is 75 micrometers high. This will allow NASA to etch a million names on the chip. 2 million names flew along with the Insight probe. As a reward you’ll get a virtual boarding pass for the flight.

Similar projects have already been done – for the launch of the Insight probe and for the first Orion test flight. If you participated in those projects too (important: the e-mail addresses have to match), then you are already a “Frequent Flyer.” You will receive your own account on the NASA website and a Mission Patch for each completed mission.

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Gas-hydrate layer keeps Pluto’s ocean warm

In 2015, the dwarf planet, Pluto, received its first visitor from Earth. NASA’s New Horizons probe sent back spectacular images that showed, among other things, the “heart” of Pluto – a region named Tombaugh Regio consisting of, among other things, the unusually light-colored Sputnik Planitia. This is a plain that is up to one to nine kilometers deep, covers approximately the surface area of Texas, and is coated with nitrogen ice.

From its existence, researchers could already assume a few things – among other things, there is probably a liquid ocean under Pluto’s surface, like the kind that also exists on the moons Enceladus and Europa. However, for Pluto, which orbits far into the outer reaches of the Solar System, it is hard to imagine that this ocean didn’t freeze solid a long time ago. For the oceans on moons, for example, it is assumed that the gravity of the giant planets that they are orbiting produces enough heat to keep them in a liquid state. Pluto doesn’t have a heating mechanism like that.

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