DIAMOND DATA
Some stars appear to contain about 1,000 times Earth’s mass in diamond dust.
Purveyors of fine jewelry might be salivating over two recent scientific reports. Or perhaps they are worried that the bottom may fall out of the diamond market.
Astronomers study the universe all across the electromagnetic spectrum, from the low frequency radio waves to high energy gamma rays. They usually can identify whatever they find by studying the spectrum, the way it looks at different wavelengths. For decades, astronomers have observed some unknown objects that emit a particular set of frequencies of microwave light, which they refer to as AME. They know it comes from some kind of rapidly spinning nanoparticles, but didn’t know what they were.
Astronomers long have known that a class of organic molecules in space, known as polycyclic aromatic hydrocarbons, or PAHs, emitted diffuse infrared radiation, and many thought they also were responsible for the AME. A given material can shine in many different wavelength bands.
“Though we know that some type of particle is responsible for this microwave light, its precise source has been a puzzle since it was first detected nearly 20 years ago,” said Jane Greaves, an astronomer at Cardiff University in Wales and lead author on a paper announcing this result in Nature Astronomy.
The new study, led by Greaves, found an IR glow around three star systems that come from nanodiamonds. These stars also emitted AME, leading the astronomers to the realization that the nanodiamonds created both types of radiation. Stars that have PAH IR-radiation don’t also show AME. Stars that do have AME contain about 1,000 times Earth’s mass in diamond dust.
Geologists know much about the composition of Earth’s interior, even though we have never been there to study it directly. They gain knowledge of the interior of our planet by analyzing seismic data. With enough data, they can accurately determine what types of rock or mineral lies at all points beneath the surface of our planet.
A craton is the deepest part of the stable interior of a continent. These extend as far as 200 miles deep into the mantle and represent the oldest existing rock on our planet. By studying the seismic data, scientists estimate that 1 to 2 percent of the cratons below each continent consists of diamond. That’s according to a new study published by a team of researchers from MIT, Harvard, the University of California at Berkeley and other institutions.
“This shows that diamond is not perhaps this exotic mineral, but on the (geological) scale of things, it’s relatively common,” said Ulrich Faul, a research scientist in MIT’s Department of Earth, Atmospheric, and Planetary Sciences who helped write the study. “We can’t get at them, but still, there is much more diamond there than we have ever thought before.”
The team estimates that more than a quadrillion tons of diamonds exist at the bottom of cratons. As of now, it’s far beyond our technological ability to get them, but in time, some will slowly work their way to the surface. Future jewelers need not worry about their livelihood.
August highlights
One of the best meteor showers occurs every year on or about Aug. 13, the Perseid meteor shower. Meteor showers happen when Earth passes through the orbital path of a comet, in this case Comet SwiftTuttle. Pebble and smaller sized debris from the comet spreads out along its orbit and we run into that debris cloud when we cross the comet’s path. We cross the midstream of the comet’s orbit in the early morning hours of Aug. 13.
An observer in ideal conditions can see one to two meteors every minute. While we won’t have such ideal conditions here, you may be able to spot one every two to three minutes. The best observing time will be midnight to 5:30 that morning. Ideally, you’ll want to get as far away from city lights as possible. Perseid meteors are known for being bright and fast-moving. The moon sets at 9:38 the previous evening, so there will be no moonlight during the prime viewing hours. This is an early Monday morning shower and school will have started for many students, so the timing isn’t the best, but it’s one of the best meteor showers you’ll see this year.
A partial solar eclipse falls on the Aug. 11, but occurs two hours before sunrise for us in Oklahoma. Go to northern Europe or northeast Asia to witness it. The next solar eclipse you can see from Oklahoma is a partial one on June 10, 2021.
Planet Visibility Report: As the month begins, Venus, Jupiter, Saturn and Mars stretch from west to east across the sky after sunset. Mars is low in the east so you may have to
wait a few hours to catch it. Mercury is totally lost in the sun’s glare. By midmonth, Mercury slowly climbs into the predawn sky, moving farther from the sun until the last week of August. The four early night planets bunch a bit closer together by the end of the month. New moon occurs on Aug. 11 during the partial solar eclipse with full moon following on the Aug. 26.
Wayne Harris-Wyrick is an Oklahoma astronomer and former director of the Kirkpatrick Planetarium at Science Museum Oklahoma. Questions or comments may be emailed to wizardwayne@ zoho.com.