Remembering Comet Hale-Bopp's Unlikely Discovery

Philipp Salzgeber // CC BY-SA 2.0 via Wikimedia Commons

Comet Hale-Bopp was a sensation in the mid-1990s. It was visible to the naked eye for 18 months, shattering a nine-month record previously set in 1811. It inspired a doomsday cult, wild late-night radio theories about extraterrestrials, and plenty of actual science. But a year before it became visible to normal observers, two men independently and simultaneously discovered it in a coincidence of astronomical proportions.

On the night of July 22-23, 1995, Alan Hale was engaged in his favorite hobby: looking at comets. It was the first clear night in his area for about 10 days, so he decided to haul out his telescope and see what he could see. In the driveway of his New Mexico home, he set up his Meade DS-16 telescope and located Periodic Comet Clark, a known comet. He planned to wait a few hours and observe another known comet (Periodic Comet d'Arrest) when it came into view. To kill time, he pointed his telescope at M70, a globular cluster in the Sagittarius system.

Comet Hale-Bopp streaks through a starry night sky.
Comet Hale-Bopp streaks through the sky over Merrit Island, Florida, south of Kennedy Space Center.
George Shelton // AFP // Getty Images

Hale was both an amateur astronomer and a professional. His interest in spotting comets was actually the amateur part, thought it would make his name famous. Hale's day jobs included stints at JPL in Pasadena and the Southwest Institute for Space Research in Cloudcroft, New Mexico. But that night, peering at M70, he wrote, "I immediately noticed a fuzzy object in the field that hadn't been there when I had looked at M70 two weeks earlier." He double-checked that he was looking in the right place, and then started to get excited.

In order to verify that the fuzzy object wasn't something astronomers already knew about, Hale consulted his deep-sky catalogues and also ran a computer search using the International Astronomical Union's computer at Harvard University. Convinced that he had found something new, Hale fired off an email very early on the morning of July 23 to the IAU's Central Bureau for Astronomical Telegrams, telling them what he had found, along with detailed instructions on how to verify it themselves. Hale also tracked the object as it moved, until it moved out of view. It was definitely a comet, and it was definitely new.

Meanwhile, Tom Bopp was in Arizona, also hunting for comets. At the time, Bopp was working at a construction materials company in Phoenix, but he was also an accomplished amateur astronomer, with decades of experience observing deep-sky objects. That night, Bopp vas visiting the remote Vekol Ranch, 90 miles south of Phoenix, known as a great location for dark-sky viewing. He was with a group of friends, which was important because Bopp didn't actually own a telescope.

The Bopp group looked through their various telescopes, observing all sorts of deep-sky objects late into the night. Bopp's friend Jim Stevens had set up his homemade 17.5-inch Dobsonian reflector telescope and made some observations. Stevens finished an observation, then left his telescope to consult a star atlas and figure out what to aim at next. While Stevens was occupied, Bopp peered into Stevens's telescope and saw a fuzzy object enter the field of view, near M70. He called his friends over to have a look.

The Bopp group proceeded to track the fuzzy object for several hours, just as Hale was doing over in New Mexico. By tracking its movement relative to background stars, they (like Hale) concluded that it was a comet. When the comet left his view, Bopp drove to a Western Union and sent a telegram to the Central Bureau for Astronomical Telegrams. (For historical perspective, telegrams were extremely outdated in 1995, but technically they were still a thing.)

Brian Marsden at the Central Bureau received Bopp's telegram hours later, after getting a few followup emails from Hale with additional details. Comparing the times of discovery, Marsden realized that the two men had discovered the comet simultaneously. According to NASA, it was the farthest comet ever to be discovered by amateur astronomers—it was 7.15 Astronomical Units (AU) from our sun. That's 665 million miles. Not bad for a pair of amateurs, one using a homemade telescope!

The Central Bureau verified the findings and about 12 hours after the initial discovery, issued IAU Circular 6187, designating it C/1995 O1 Hale-Bopp. The circular read, in part: "All observers note the comet to be diffuse with some condensation and no tail, motion toward the west-northwest."

Four men smile, posing outdoors next to a large telescope at night.
Comet hunters (L to R): David Levy, Dr. Don Yeomans, Dr. Alan Hale and Thomas Bopp pose next to a telescope during a public viewing of the Hale-Bopp and Wild-2 comets.
Mike Nelson // AFP // Getty Images

Less than a year later, Comet Hale-Bopp came into plain view, and the rest is history. It was a thousand times brighter than Halley's Comet, which had caused a major stir in its most recent appearance in the 1980s. Comet Hale-Bopp will return, much like Halley's Comet, but it won't be until the year 4385. (And incidentally, it was previously visible circa 2200 BCE.)

The Northern Lights May be Visible in New York, Michigan, and Illinois on Saturday

The Northern Lights, a meteorological event most common to areas north of the Arctic Circle, may be visible over parts of America this weekend, Newsweek reports. Due to a solar storm, the light show may appear Saturday night over states in the northern part of the contiguous U.S., including New York, Michigan, Illinois, and Washington state.

Aurora borealis, or the Northern Lights, occur when solar particles react to gases in Earth's atmosphere. Magnetic energy exaggerates this effect, which is why auroras most often appear at the geomagnetic poles where Earth's magnetic field is strongest. Rare circumstances can produce this phenomenon at lower latitudes, which may be the case this weekend.

On Wednesday, March 20, a solar flare sent a blast of solar particles toward Earth. The resulting geomagnetic storm could make for a vibrant and colorful aurora reaching as far south as New York and Wisconsin.

To catch the spectacle, look up at the night sky on Saturday, March 23. People in areas with minimal light pollution have the best chance of seeing the Northern Lights, though cloudy weather may make them hard to see.

[h/t Newsweek]

5 Fast Facts About the Spring Equinox

The northern hemisphere has officially survived a long winter of Arctic temperatures, bomb cyclones, and ice tsunamis. Spring starts March 20, which means warmer weather and longer days are around the corner. To celebrate the spring equinox, hear are some facts about the event.

1. The spring equinox arrives at 5:58 p.m.

The first day of spring is today, but the spring equinox will only be here for a brief time. At 5:58 p.m. Eastern Time, the Sun will be perfectly in line with the equator, which results in both the northern and southern hemispheres receiving equal amounts of sunlight throughout the day. After the vernal equinox has passed, days will start to become shorter for the Southern Hemisphere and longer up north.

2. The Equinox isn't the only time you can balance an egg.

You may have heard the myth that you can balance on egg on its end during the vernal equinox, and you may have even tried the experiment in school. The idea is that the extra gravitational pull from the Sun when it's over the equator helps the egg stand up straight. While it is possible to balance an egg, the trick has nothing to do with the equinox: You can make an egg stand on its end by setting it on a rough surface any day of the year.

3. Not every place gets equal night and day.

The equal night and day split between the northern and southern hemispheres isn't distributed evenly across all parts of the world. Though every region gets approximately 12 hours of sunlight the day of the vernal equinox, some places get a little more (the day is 12 hours and 15 minute in Fairbanks, Alaska), and some get less (it's 12 hours and 6 minutes in Miami).

4. The name means Equal Night.

The word equinox literally translates to equal ("equi") and night ("nox") in Latin. The term vernal means "new and fresh," and comes from the Latin word vernus for "of spring."

5. The 2019 spring equinox coincides with a supermoon.

On March 20, the day the Sun lines up with equator, the Moon will reach the closest point to Earth in its orbit. The Moon will also be full, making it the third supermoon of 2019. A full moon last coincided with the first day of spring on March 20, 1981, and it the two events won't occur within 24 hours of each other again until 2030.