A comet will flyby Mars next weekend, barely missing the Red Planet but providing a show that will be captured by NASA's fleet of spacecraft.
Comet Siding Spring will pass within 87,000 miles of Mars, or one-third of the distance between Earth and the moon, on Sunday, Oct. 19, according to the space agency.
The comet will come closest to Mars at approximately 2:27 p.m. that day, moving at around 34 miles per second.
"On October 19, we're going to observe an event that happens maybe once every million years," Jim Green, director of NASA's planetary science division, said during a news conference today (Oct. 9). "We're getting ready for a spectacular set of observations."
Comet Siding Spring, also known as C/2013 A1, was discovered in 2013 by astronomer Rob McNaught using Australia's Siding Spring Observatory.
The comet is currently making its first trip through the inner solar system from the frigid Oort Cloud, which lies around 50,000 units from the sun, according to Space.com. (One astronomical unit, or AU, is the average distance between Earth and the sun, about 93 million mile.)
Since Siding Spring has never been "heat-treated' before, the incoming comet remains mainly unchanged since its formation some 4.6 billion years ago, researchers said.
"That's one of the reasons we study comets, they're the remnants of our solar system's formation," said Padma Yanamandra-Fisher, a senior research scientist at the Space Science Institute's Rancho Cucamonga branch in California, according to Space.com.
Researchers think the comet's core is around 0.5 miles and 5 miles in diameter. The fuzzy cloud (or coma) surrounding Siding Spring's nucleus is about 100,000 miles wide at this point, and its tail stretches for about 300,000 miles, scientists said.
NASA is hoping to learn more about the comet's size, rotation speed, activity, and composition.
The Mars Reconnaissance Orbiter (MRO) will take the first-ever good pictures of an Oort Cloud comet's nucleus if things go according to plan. Opportunity and Curiosity could make some history as well.
"We certainly have fingers crossed for the first images of a comet from the surface of another world," said Kelly Fast, program scientist at NASA's planetary science division, according to Space.com. "That would be really exciting."