It doesn't matter whether you think Pluto is a planet or not. Do you know how close it is to the sun?
Posted on July 30, 2015, at 10:57 a.m. ET
That's why the sun rises in the east.
Mars is about half the width of Earth.
Both Mercury and Venus are moon-less.
Between February 1979 and February 1999 Pluto's elliptical orbit brought it closer to the sun that Neptune. It will cross over again in just over 200 years from now.
It's one of the Galilean moons, along with Europa, Ganymede and Callisto.
Makemake is a dwarf planet in the Kuiper belt.
The Large Magellanic Cloud is a satellite of our own galaxy, so its closer. Andromeda is the largest galaxy in the Local Group and is over ten times further away than the LMC.
51 Pegasi b was discovered in 1995.
It's the ninth brightest star in the night sky.
It's the remnant of a supernova. The other nebula above is the Orion nebula.
Hydrogen and helium were formed in the big bang, and everything else was formed in stars.
The red shift of distant galaxies shows that galaxies further away from us are moving quicker, suggesting that the universe is expanding.
A supernova can form a black hole or a neutron star. A white dwarf form when a star doesn't have a large enough mass to go supernova.
It's named after Subrahmanyan Chandrasekhar, the physicist who independently calculated the limit at the age of 19 in India. The Planck mass is much, much, much smaller.
And Opportunity is still roving!
Voyager 1 is the furthest human-made object from Earth, and it's just left the solar system. It's next stop is a star called AC +79 3888 40,000 years from now.
Vega 2 was a Soviet probe that landed on Venus in 1985. There have been flybys of the planet since, but no more landings.
The mirror was two microns too flat, and wasn't able to produce images as good as hoped.
All for just a few hours taking data when it got there – though analysis will take a lot longer.
Kelly Oakes is science editor for BuzzFeed and is based in London.
Contact Kelly Oakes at firstname.lastname@example.org.
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