This month NASA released a year-long time lapse of the Earth as seen by its Deep Space Climate Observatory (DSCOVR) mission orbiting the Sun in sync with us.
You may have already seen a few releases from the Earth Polychromatic Imaging Camera (EPIC) camera abroad the spacecraft, most notably its a first-light image last July and earlier this month when the Moon briefly photobombed the Earth.
DSCOVR is over a million miles away from us, but it is able to stay in orbit directly between Earth and the Sun thanks to a gravitational point of stability known as a Lagrange Point, where the pull between two masses is balanced. In the Sun-Earth system, there are five such points - DSCOVR orbits at the first one (L1) which is a point between the Sun and the Earth where the pull of both bodies on the spacecraft is equal. In this position, the side of Earth facing the spacecraft is always fully illuminated by the sun. DSCOVR's mission is to observe the solar wind (aka space weather) and provide advance warnings when magnetic storms and flares are headed our way, but its unique vantage point also enables it to provide valuable data on Earth's atmosphere and climate.
For the past year, EPIC has taken a photo of Earth every two hours which NASA has now used to create a time-lapse video. EPIC has ten different filters, but only a subset of them (red, green, and blue) were used to create these images. The video below is narrated by Jay Herman, the lead scientist on EPIC, who explains the mission while the Earth goes through a full year. It's fascinating to pick a hemisphere or latitude and see how the cloud cover changes (or doesn't) day to day and month to month.
Here's some more geek from the week: