NASA’s Scout system, which is located at NASA’s Jet Propulsion Laboratory in Pasadena, California, flagged a newly discovered comet object as possibly being interstellar. if confirmed as interstellar, it would be only the second such object detected. The first, the infamous Oumuamua, was discovered by researchers from the University of Hawaii -supported by the NASA Astrobiology Institute- on Oct. 19, 2017, more than a month after it passed its closest point to the Sun. They named the object after the Hawaiian word for “scout.” In the months that followed it’s detection, ‘Oumuamua’s behavior baffled astronomers leading some to view the cosmic prodigy as an alien probe.
Encountering a piece of advanced technology developed by an extraterrestrial intelligence “might resemble an imaginary encounter of ancient cave people with a modern cell phone,” said Harvard’s Avi Loeb. “At first, we would interpret it as a shiny rock, not recognizing it as a communication device. The same thing might have happened in reaction to the first detection of an interstellar visitor to the solar system, Oumuamua (image above), which showed six peculiar properties but was nevertheless interpreted as a rock by mainstream astronomers.”
The New Visitor from Afar
The new object – designated C/2019 Q4 (Borisov) – was discovered on Aug. 30, 2019, by Gennady Borisov at the MARGO observatory in Nauchnij, Crimea. The official confirmation that comet C/2019 Q4 is an interstellar comet has not yet been made, but if it is interstellar, it would be only the second such object detected.
C/2019 Q4, is still inbound toward the Sun, but it will remain farther than the orbit of Mars and will approach no closer to Earth than about 190 million miles (300 million kilometers).
After the initial detections of the comet, the Scout system automatically flagged the object as possibly being interstellar. Davide Farnocchia of NASA’s Center for Near-Earth Object Studies at JPL worked with astronomers and the European Space Agency’s Near-Earth Object Coordination Center in Frascati, Italy, to obtain additional observations. He then worked with the NASA-sponsored Minor Planet Center in Cambridge, Massachusetts, to estimate the comet’s precise trajectory and determine whether it originated within our solar system or came from elsewhere in the galaxy.
The comet is currently 260 million miles (420 million kilometers) from the Sun and will reach its closest point, or perihelion, on Dec. 8, 2019, at a distance of about 190 million miles (300 million kilometers).
“The comet’s current velocity is high, about 93,000 mph [150,000 kph], which is well above the typical velocities of objects orbiting the Sun at that distance,” said Farnocchia. “The high velocity indicates not only that the object likely originated from outside our solar system, but also that it will leave and head back to interstellar space.”
Currently on an inbound trajectory, comet C/2019 Q4 is heading toward the inner solar system and will enter it on Oct. 26 from above at roughly a 40-degree angle relative to the ecliptic plane. That’s the plane in which the Earth and planets orbit the Sun.
C/2019 Q4 was established as being cometary due to its fuzzy appearance, which indicates that the object has a central icy body that is producing a surrounding cloud of dust and particles as it approaches the Sun and heats up. Its location in the sky (as seen from Earth) places it near the Sun – an area of sky not usually scanned by the large ground-based asteroid surveys or NASA’s asteroid-hunting NEOWISE spacecraft.
C/2019 Q4 can be seen with professional telescopes for months to come. “The object will peak in brightness in mid-December and continue to be observable with moderate-size telescopes until April 2020,” said Farnocchia. “After that, it will only be observable with larger professional telescopes through October 2020.”
Observations completed by Karen Meech and her team at the University of Hawaii indicate the comet nucleus is somewhere between 1.2 and 10 miles (2 and 16 kilometers) in diameter. Astronomers will continue collect observations to further characterize the comet’s physical properties (size, rotation, etc.) and also continue to better identify its trajectory.
Back to Oumuamua
Back to the original Oumuamua story which started when Avi Loeb reported that our paper considers the possibility that life could be transported across the entire Milky Way galaxy and beyond: “The solar system acts as a gravitational ‘fishing net’ that contains thousands of bound interstellar objects of this size at any given time. These bound interstellar objects could potentially plant life from another planetary system and in the solar system.”
All hell broke loose in fall of 2018 when Loeb followed up with a new paper suggesting that the interstellar object might be “a spaceship, a lightsail, from an alien civilization.”
Loeb has spent much of his amazing career searching for alien life. In addition to his myriad Harvard hats (Director of Harvard’s Black Hole Initiative and Director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics), he’s the chair of the Breakthrough Starshot Advisory Committee, a $100 million initiative that is currently listening for signs of aliens.
The Daily Galaxy, Max Goldberg, via NASA/JPL