Cassini Spacecraft To Take Picture Of Earth From Nearly 900 Million Miles Away
Lawrence LeBlond for redOrbit.com – Your Universe Online
The jointly operated NASA/ESA/ASI Cassini-Huygens orbiter exploring Saturn is set to take a spectacular image of Earth on the afternoon of July 19 during a solar eclipse of the sixth planet. Earth will actually appear as a small, pale blue dot between the rings of Saturn during the mosaic imaging event.
NASA has invited the public to help acknowledge the interplanetary portrait by waving up to the skies when the image is taken. Cassini will begin taking images of Earth at 5:27 p.m. EDT and end about 15 minutes later. While Saturn will be eclipsing the sun from Cassini’s point of view, most of North America and part of the Atlantic Ocean will be in sunlight.
“While Earth will be only about a pixel in size from Cassini’s vantage point 898 million (1.44 billion kilometers) away, the team is looking forward to giving the world a chance to see what their home looks like from Saturn,” said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “We hope you’ll join us in waving at Saturn from Earth, so we can commemorate this special opportunity.”
While Cassini has taken Earth´s image twice before — once in 2006 and once in 2012 — during its past nine years in orbit of Saturn, this will be the first time the orbiter will capture the Earth in its natural color, as human eyes would see it. This will also be the first time Cassini will capture our moon using its high-resolution camera. Because Saturn will be in eclipse from Cassini´s point of view, its sensitive detectors will be able to turn in the direction of the sun, where Earth will be, and snap images.
“This time, the images to be collected will capture, in natural color, a glimpse of our own planet next to Saturn and its rings on a day that will be the first time Earthlings know in advance their picture will be taken from a billion miles away,” said Carolyn Porco, Cassini imaging team leader at the Space Science Institute in Boulder, Colorado.
Porco added that she has been waiting six long years to have another moment to capture the Earth in a breathtaking mosaic. The 2006 image was heralded as one of Cassini´s “most beloved images,” yet Porco wants to “do it all over again, only better.”
Porco expressed that everyone around the globe has the chance to be part of this historic moment and “savor the uniqueness of our planet and the preciousness of the life on it.”
While examining Cassini’s flight path during the remainder of its mission at Saturn, Porco and staff members from CICLOPS found that July 19, 2013 would be the next best opportunity for the spacecraft to conduct a mosaic portrait of Saturn, its rings and Earth in the distance while hiding in the Saturnian shadows.
July 19 will also give astronomers the best chance to capture Saturn and its ringed system in both visible and infrared imagery.
“Looking back towards the sun through the rings highlights the tiniest of ring particles, whose width is comparable to the thickness of hair and which are difficult to see from ground-based telescopes,” said Matt Hedman, a Cassini science team member based at Cornell University in Ithaca, New York, and a member of the rings working group. “We’re particularly interested in seeing the structures within Saturn’s dusty E ring, which is sculpted by the activity of the geysers on the moon Enceladus, Saturn’s magnetic field and even solar radiation pressure.”
While the imaging project has scientific implications in mind, Porco hopes that people everywhere on Earth will embrace the moment Earth poses for Cassini.
“My sincere wish is that people the world over stop what they’re doing at the time the Earth picture is taken to revel in the sheer wonder of simply being alive on a pale blue dot of a planet, and to appreciate the ever-widening perspective of ourselves and our world that we have gained from our interplanetary explorations. We are dreamers, thinkers, and explorers, inhabiting one achingly beautiful planet, yearning for the sublime, and capable of the magnificent. Let’s celebrate that, and make this one day a day the whole Earth smiles in unison,” she said in a statement.
The latest image will be a continuance of NASA space-based images of the Earth, the first ever becoming the 1968 “Earthrise” image taking during the Apollo 8 moon mission from about 240,000 miles away. Voyager 1 also took a snapshot of the “Pale Blue Dot” in 1990 from nearly 4 billion miles away, an event that Porco co-initiated and executed.
The Cassini-Huygens mission is a joint project of NASA, the European Space Agency and the Italian Space Agency. The mission is managed by the Jet Propulsion Laboratory, a division of Caltech, as part of NASA´s Science Mission Directorate in Washington, DC.
The Cassini orbiter and its two main cameras were designed, developed and assembled at JPL. The imaging team consists of scientists from the US, England, France and Germany. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.