Endeavour delivers the Alpha Magnetic Spectrometer/update on Gliese 581d

May 18, 2011

Endeavour launched through a low deck of clouds Monday morning. Credit: NASA

As I’m sure you know, Space Shuttle Endeavour launched Monday morning, and is now docked with the International Space Station. I want to point out one very special part of this mission that could change mankind’s understanding of the universe forever- the Alpha Magnetic Spectrometer. This device is the brainchild of Nobel Prize winner Professor Samuel Ting. It cost about $2 billion to build, but the knowledge gained from it will be well worth the money. The device will be mounted on the exterior of the ISS and will run its experiments for the rest of the duration of the ISS (currently the ISS is to be funded and run through 2025). Basically, this amazing piece of equipment has a ring of immensely powerful magnets that will bend the path of any nearby cosmic rays so that they pass through a very sensitive detector. The velocity of these cosmic rays out in space is many orders of magnitude greater than anything we can create in a collider here on Earth (the Large Hadron Collider, for example). These rays do hit the Earth’s atmosphere, but most of them are scattered, deflected, or broken up by the ozone layer. That’s why this space-based experiment is so important. The main things Ting will be looking for are evidence of antimatter, dark matter/dark energy, strangelets, and other aspects of cosmic radiation that could affect future missions involving manned spaceflight. For a good breakdown of each of these scientific objectives, visit the AMS’s official website. The wikipedia page and this space.com article are also pretty good.

It’s been a while since I’ve talked much about exoplanets- one of my favorite areas of science and astronomy. I’m happy to report that our old friend Gliese 581 has yet another surprise: one of its well-confirmed planets may actually have liquid water on its surface, which means the temperature range would generally be suitable for human life. For a few years now we’ve known about several planets orbiting this red dwarf star that sits about 20 light-years away from us. The latest exoplanet discovery associated with this system (Gliese 581g) is being hotly contested, so it may not even exist at all, but the one we’re now talking about is certain to exist. It could be a while before we can definitively say whether or not this exoplanet (Gliese 581d) actually has liquid water on its surface, but a new set of computer models/simulations has shown that if the atmosphere of this rocky super-earth is dense enough, it would be stable and keep the temperature range suitable for liquid water, and possibly even life. This all hinges on an assumption that this world has a thick atmosphere full of CO2, so scientists aren’t really certain about the climate. But, based on what is known about planet formation and the makeup of Gliese 581d, a thick CO2 atmosphere is very likely to exist. This is certainly not the “holy grail of planet-hunting” a.k.a. an earth-twin because the planet is about twice the size of Earth/has about 7 times the mass, is tidally locked (meaning the same side always faces its star), and has an atmosphere of mostly CO2. Indeed, if life exists at all on this world, it would be vastly different from what’s found on Earth, but this news is very exciting nonetheless.


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