Astronomy March 2021

Follow the Dave’s Universe blog: www.Astronomy.com/davesuniverse Follow Dave Eicher on Twitter: @deicherstar When you click on the TV and escape this crazy world with a film, maybe you’re a sci-fi fan. Do you glimpse Godzilla? Revere zombies or Terminators? Whichever way you go, you might be overlooking the most terrifying monsters of them all: black holes. Encountering a live black hole would be a harrowing experience — at least briefly. Depending on the black hole’s mass, it would most likely pull you into a miles-long string of protons — “spaghettify” you — as you fell into the event horizon, making movie monsters pale in comparison. The physics of black holes has been worked out only in the last generation or two, but the concept goes back a very long time. In 1783, the English…

Astronomy’s leading lady I would like to point out that, on the stamp commemorating the 150th anniversary of the Royal Astronomical Society (from your November story, “Collect the cosmos in stamps”), there are four people depicted: William Herschel, John Herschel, Francis Baily, and off to the right the silhouette is Caroline Herschel. She was William’s right hand, John’s first teacher of astronomy, the first woman to be salaried as an astronomer, and the discoverer of eight comets; rewrote Flamsteed’s catalog correcting his mistakes; and made it easier for astronomers to view the night sky. — K. Lynn King Author Katrin Raynor responds: While Caroline Herschel is certainly worthy of recognition, the profile on the stamp is the head of Queen Elizabeth II. Science meets art Thank you for your portrait of Galileo as an…

Researchers think the Moon was formed when Earth was struck by a Mars-sized body, known as Theia, early in the solar system’s history. These snapshots from a simulation published October 29 in The Astrophysical Journal Letters capture the terrifying and beautiful dynamics of such a collision. In the first three frames (top row), which cover a time frame of 30 minutes, the impactor gouges out a massive chunk of Earth, blasting debris into space. Over the following 10 hours (middle row), much of that debris rains back down to Earth, including huge fragments that have completed as much as half an orbit. Within 48 hours after the impact (bottom row), the remaining orbital debris has begun to form a disk of material that surrounds Earth. These remnants will eventually coalesce, forming…

SWITCHING PARTNERS The rocket that launched NASA’s Surveyor 2 probe to the Moon in 1966 went on to orbit the Sun — until November 2020, when Earth recaptured it. After temporarily orbiting our planet, it will return to circling the Sun in March 2021. GREAT HEIGHTS New research shows that dust storms on Mars can loft water vapor high into the atmosphere, where it escapes or is destroyed by radiation. This could explain how the Red Planet has lost — and continues to lose — its water. FIRST FOUND Astronomers using the Low Frequency Array in Europe have detected a brown dwarf’s weak magnetic field, a first for any radio telescope. This paves the way to finding more such objects, which have masses between planets and stars.…

After 57 years of cutting-edge research and pop culture fame that inspired generations of scientists, the legendary Arecibo radio telescope in Puerto Rico was destroyed on December 1 when its receiving platform collapsed and came crashing down onto the dish below. A series of cable failures doomed the massive facility. First, on August 10, an auxiliary cable that helped suspend the 900-ton receiving platform slipped out of its socket on one of three support towers that surround the observatory, tearing a 100-foot (35 meters) gash in the dish. Then, on November 6 — just days before repairs were set to begin — one of the main cables attached to that same support tower snapped, likely due to the increased load it was bearing. That put the structure at risk of total collapse —…

As Europa orbits Jupiter, it endures constant radiation from its host planet’s magnetic field. Night and day, energy rains onto Europa, making the moon’s ice-and-salt surface glow in the dark. Researchers also believe the nightside glow holds clues to whether Europa could sustain life. To answer that question, scientists looked at the way organic material reacted to similar blasts of radiation in the lab and uncovered something unexpected: variation in how different ice-salt compositions glowed. This means that Europa likely glows brighter in some spots than others, which can be seen in this artist’s illustration.…