Today, April 22, is Earth Day. It’s a day intended to reinforce the environmental movement, and to honor—and admire—the planet we call home.
As it happens, this is also the week of the 25th anniversary of the Hubble Space Telescope, one of Earth’s greatest scientific creations. Twenty-five is ancient in satellite-years, and the grizzled veteran telescope is about ready to hang up its boots.
With its parts degrading and its orbit decaying, NASA must figure out a way to safely decommission Hubble. It will either launch a mechanism into space to rendezvous with the telescope and usher it back to Earth, or propel it deeper into space, where it will float on in perpetual loneliness. We prefer the first scenario.
Hubble can take photos of pretty much everything in our universe except the Earth. It was designed to snap photos of distant objects, which requires a very long exposure time. According to the Hubble website, the telescope’s shortest possible exposure time is 0.1 seconds, and in that span it travels nearly half a mile in Earth’s orbit. So even if the lens were pointed at Earth, the resulting image would not be decipherable.
But other satellites and astronauts flying nearby have taken incredible photos of Hubble with Earth as its backdrop. They allow us to glimpse at the most important telescope ever made with the planet that created it.