Last week, a celebrity favorite here at Sci Show -- the
visionary billionaire Elon Musk – displayed the first crewed spacecraft to be
unveiled in the U. S. since 1981.
Meanwhile, a planet somewhat like Earth, only bigger, is making heads get
scratched and minds be blown as it challenges our theories about how planets
form -- and how the universe itself evolved. Welcome to SciShow Space News. On Monday,
astronomers from the Harvard-Smithsonian Center for Astrophysics announced they'd
discovered a whole new class of exoplanet -- a kind of giant terrestrial world
they call a mega-Earth. This new category is based on a planet first observed
by the Kepler Space Telescope in May 2011, an alien world known as Kepler-10c.
When Kepler observed the planet transiting across its star, Kepler 10,
astronomers measured it to be about two-and-a-half times the size of Earth. And
because of its size, they assumed it was a type of planet called a
Mini-Neptune, with a terrestrial core a little bit denser than Earth's and
enough gravitation to accumulate a thick atmosphere of hydrogen and helium. But
astronomers followed up their Kepler observation with another instrument in the
Canary Islands, known as the HARPS-N.
And using its spectrometer, they found that the orbit of the star
Kepler10 was being pulled on by a truly massive object. It turned out that
Kepler-10c was about 17 times as massive as Earth -- much more than anyone
expected. And for anything to be that
heavy, it's got to be rock, all rock, and really dense rock! Which is kind of
problematic, because that kind of density just. . . doesn't make sense. First
of all, there's not all that much solid material out there. Hydrogen and helium
are much more abundant than the elements like silicon and iron which make rock.
And we've long thought that planets with about ten times the mass of Earth
would necessarily attract thick layers of gas with their gravity. So we've been
assuming that all the massive planets we find are gas giants like Jupiter. But
Kepler-10c challenges that assumption, and astronomers aren't sure how that can
be. It also challenges our theories about how the whole universe formed. Early in the universe's14 billion year-life,
everything was made out of the two lightest and simplest elements, hydrogen and
helium. Generations of stars fused those
elements into heavier and heavieratoms, eventually resulting in elements like
iron that make up rock. But the Kepler-10 star system formed 11 billion years
ago, before the first generations of stars had time to create such
materials. So where did the rock come
from? Astronomers are pretty dumbfounded. So thanks a lot, Kepler-10c. I guess it's back to the drawing board. Finally, NASA
astronauts are done catching rides with the Russians. Last week, SpaceX CEO
Elon Musk unveiled the first manned American spacecraft to be available since
the closing of the NASA shuttle program in 2011. Now SpaceX's Dragon V2 will be
available to shuttle astronauts to the International Space Station from US soil
for the low price of twenty million dollars.
It'll bring them back, too--taking up to ten space trips in its
lifetime. It's a pretty awesome little machine.
Capable of transporting seven people, the craft has the first fully
printed engine, called the Super Draco, made with an alloy of nickel andiron.
Dragon V2 has eight of these powerful and spontaneously igniting Super Dracos,
which Musk says will propel the craft with the maneuverability of a helicopter,
allowing for precise docking and re-entry. And a state-of-the-art heat shield
will protect the crew during re-entry into Earth's atmosphere. Dragon V2 will
take its first test flight later this year.
And we can't wait! Thanks for joining me for this update for the week's
space news.
Source: SciShow Space
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