Terry Lovejoy has discovered five comets from his home since 2007—something that's become harder and harder for humans to do.
A photo of one of Terry Lovejoy's earlier comet discoveries, taken from the International Space Station in 2011. Photo: NASA/Flickr
Who hasn't felt a small thrill when looking up into the night sky and picking out the Moon, one of the planets or some easily recognizable constellations—say, Orion, or the Big Dipper? But for Australian comet hunter Terry Lovejoy, the thrill is personal. When Lovejoy looks up at the sky, he can see a comet named after him—a comet he discovered from his home in Brisbane, Australia, and his fifth discovery since 2007.
This week, Comet C/2014 Q2 Lovejoy is in prime position for observers in the northern hemisphere to see, travelling past the constellations Orion and Taurus at approximately 130,000 kilometers per hour. By the end of the week, it will be visible near the spectacular Pleiades star cluster. If you are in a location with dark skies, you might even be able to see the comet without binoculars.
And while the comet itself is not particularly special—its next visit to the inner solar system will not occur for another 8,000 years, nor will it be extremely bright in the night sky—the way it was discovered is becoming increasingly rare. Automated sky surveys conducted by arrays of large professional telescopes and cameras are finding more and more comets further from Earth, so dim they are not even visible with amateur instruments, edging people such as Lovejoy out.
But the 48-year-old Aussie does have one advantage: his location. "Being in the southern hemisphere means we have access to parts of the sky which are not visible from the northern hemisphere, where most of the major surveys are," Lovejoy said, "So there is less competition."
Even that is changing, though. Richard Wainscoat, an astronomer at the University of Hawaii who works on the Panoramic Survey Telescope & Rapid Response System (Pan-STARRS), explained that the sky survey's reach is expanding to include much of the southern hemisphere. Only two of four planned Pan-STARRS scopes have been built so far, but already, he said, Pan-STARRS' surveys accounted for 33 of 65 newly discovered comets in 2014.
Karl Battams, an astrophysicist based at the Naval Research Laboratory in Washington, D.C. and head of the NASA-funded Sungrazer Project, which searches for comets passing close to the Sun, lamented that, "We have lost the tradition and romanticism of a guy going out at night and randomly pointing his telescope to the sky and discovering a new comet and having it named after him."
"But, on the flip side," Battams said, "the value and the quality and the quantity of science that amateur astronomers can now bring to the table is just unprecedented and it's really extremely important."
That is because, for all their power, the big professional telescopes do have limitations that amateurs do not. For example, the big scopes cannot examine objects that are too close to the Sun, which could damage their sensitive (and expensive) optics. Amateurs, on the other hand, can do whatever they want with their telescopes without worrying about damage to $100 million instruments—the expected cost for the four Pan-STARRS scopes.
Lovejoy's technique involves taking three photos of the same patch of sky at 10-minute intervals. Using specialized software, he compares the images to see if any of the "stars" have moved. While actual stars do not appear to move relative to each other, comets do show movement, even in such a short time span. When he identifies a potential comet, Lovejoy makes further observations, double-checking his findings with other amateur astronomers, before contacting the Central Bureau for Astronomical Telegrams (CBAT), located at Harvard University, where new discoveries are vetted and verified.
"I don't feel the urgency I did with my first comet," Lovejoy told Motherboard, "but I'm always mindful that the folks at CBAT don't have time to deal with false alarms, so I try to verify my observations. I have yet to send them a false alarm and want to keep it that way!"
While there is a detailed set of rules for the naming of comets, they are most often named after the person or people responsible for the discovery—or, increasingly, the survey program that discovers them (Comet Pan-STARRS and Comet LINEAR just do not have the same ring as Comet Lovejoy or Comet McNaught, though).
"We have lost the tradition and romanticism of a guy going out at night and randomly pointing his telescope to the sky and discovering a new comet and having it named after him."
Another area where amateurs still hold an advantage over professionals is that they can sometimes collect and share data on previously known discoveries using their backyard telescopes faster than researchers can gain access to their multi-million dollar rigs. It may be less glamorous than discovering your own comet, but it is still important work.
"There are plenty of objects in the sky that astronomers are always wanting to look at and study—not just comets," Battams said. "You have to book well in advance time on these telescopes. And so, suddenly, when a big, bright, interesting comet comes along, all of the comet scientists may be bouncing up and down in their seats wanting to observe it. But if you have a whole bunch of other astronomers that don't care about comets and they've already booked telescope time, you can't really go kicking them off just because a comet scientist got excited."
Amateurs, however, have no such limitations. If an exciting new discovery is made, they can swing their scopes in that direction at a moment's notice.
When asked about his future goals, Lovejoy was unequivocal. "Well, discover more comets!" he exclaimed. "But I am working to make the programs and detection processes more efficient. Perhaps expand out to detection of other transient objects like novas and perhaps even supernovas. This keeps my interest up."
Well, that and the potential of having another comet with his name on it.