For those who follow my site, or just pay attention to a reliable news source, you may recall that NASA announced an opportunity to take part in a long-range photo op. REALLY long range. A few weeks ago, in an attempt to raise awareness about Jupiter and space exploration, NASA announced that the Cassini Space Probe would be rounding Saturn and snapping photos of a distant Earth.
The worldwide “Wave at Saturn” campaign encouraged people to look up at the skies as the probe took its shots. Junior astronomers were also encouraged to watch with their telescopes to see if they could spot the distant satellite performing its route around the massive, ringed planet. This marked the first time that NASA was able to give the people of Earth advanced warning about a space photo op, and the turnout was impressive.
Granted, North America and part of the Atlantic Ocean were the only illuminated parts of Earth at the time, but NASA claims that more than 20,000 people came out to wave at Saturn and post pictures of themselves online. Given the enormous distance involved, Earth itself appeared only 1.5 pixels wide in the photos. So congratulations if you got in the picture, but don’t expect to be able to see you face.
Not to be left out, members of NASA’s Jet Propulsion Laboratory in Pasadena gathered outside of the facility to wave at Cassini on July 19th as it rounded the Saturnalian system and snapped shots of North America. Camping out on the front lawn, researchers and scientists set up a pavilion for the afternoon and enjoyed some outdoor fun until the moment arrived to wave at the heavens.
After being beamed back to Earth from 1.5 billion km away (over a billion miles), NASA science teams got right to work processing the many photos shot by Cassini so they could create individual color composites and a panoramic view of the ‘pale blue dot’ of Earth as well as the entire Saturnalian system. And as you can see from the image posted at the beginning of this article, the first color composite was pretty damn spectacular!
Cassini took a total of 323 images using different spectral filters. The snapshots it took of Earth happened between 2:27 and 2:42 p.m. PDT on Friday, July 19 from a distance of about 1.44 billion kilometers (898 million miles). The images show the Earth and the Moon as dots barely about a pixel wide but do reveal the ‘pale blue dot’ that is home to all of humanity and our whitish colored neighbor.
Distant views of the Earth from robotic space probes, especially from the outer reaches of our Solar System, are few and far between, and are therefore events for space and astronomy enthusiasts and everyone else to savor. The last time Cassini took mosaic pictures of Saturn and Earth was back in 2006, and those were pretty spectacular too. But on this occasion, the benefits went beyond stunning photographs.
Linda Spilker, Cassini project scientist of NASA’s Jet Propulsion Laboratory, explained:
One of the most exciting Cassini events in 2013 will be the unusual opportunity on July 19 to image the whole Saturn system as it is backlit by the sun. With Saturn covering the harsh light of the sun, we will be gathering unique ring science and also catching a glimpse of our very own home planet.
Coincidentally, the first humans (Neil Armstrong and Buzz Aldrin) set foot on the Moon 44 years ago nearly to the day of Cassini’s new images on July 20, 1969. In short, this occasion reminds us that not only do we live in a very vast universe, but that we are part of a very proud and ongoing tradition of exploration.