NASA/APL/Southwest Research Institute
The "movie" above may not look like much, but it's one of the most incredible things you're likely to see today. That little white dot is the on-again/off-again planet Pluto, being orbited in the vast emptiness of space by its moon, Charon, for an entire day.
The time-lapse was captured by NASA's New Horizons spacecraft, which is currently staking out Pluto before its close encounter in July this year.
The images were captured when New Horizons was between 203 and 195 million kilometres away from Pluto, which, when you think of the more than 3 billion miles that the spacecraft has ventured from Earth, is excitingly close. Shot over a week in January, each frame has an exposure time of just one-tenth of a second, which isn't long enough to see Pluto's much smaller and fainter moons.
The images capture an entire rotation of each body, which corresponds to a full Pluto "day" - the equivalent of around 6.4 Earth days. You can also see Pluto wobble as Charon orbits it, due to the gravitational pull of the moon, which is roughly the size of Texas.
A NASA press release explains:
"The time-lapse frames in this movie were magnified four times to make it easier to see Pluto and Charon orbit around their barycentre, a mutual point above Pluto's surface where Pluto and Charon's gravity cancels out – this is why Pluto appears to "wobble" in space. Charon orbits approximately 11,200 miles (about 18,000 kilometres) above Pluto's surface."
You can see the full, zoomed-out time-lapse below. New Horizons is scheduled to get up close and personal with Pluto and Charon on July 15th, and these images will help mission scientists better understand what to expect.
This is the first time a spacecraft (that we know of) has ever been this close to Pluto, and it's pretty exciting to imagine what we might learn.
NASA/APL/Southwest Research Institute
Source: NASA