Each year, on April 22 we celebrate Earth Day, a special day to honour the best planet in the entire universe! It’s also a day to appreciate our small and fragile oasis in space. From over 2,000 planets discovered orbiting other stars, only about 30 have the potential to be habitable. Earth is still the only known harbours life.

The phrase “Pale Blue Dot” came from the 1990 image of Earth from Voyager 1, taken when it reached the edge of our Sun’s planetary system. Looking back from the gas giant planets, Earth appears to be nothing more than a pale blue dot in the darkness. Previously, Earth had been referred to as the “Blue Marble,” a phrase coined by the crew of Apollo 17 in 1972 when they took one of the most widely distributed images ever. This photo showed the astronauts view of Earth, appearing no larger than a glass marble. What might our future view of Earth look like? Will we one day travel so far that our Sun will be a pale yellow dot?

You may have seen this before but we think there is no better summary of how important Earth is than Carl Sagan’s Pale Blue Dot – watch here.

You can find out more about the Earth Day Network and make a donation towards tree planting at www.earthday.org.