by Kim Malville
What’s happening in the skies this month
Jupiter is the king this month, brilliant, half-way up the sky between the constellations of Cancer and Leo. Just to the left of Jupiter is Regulus the brightest star in its vicinity. Compare how differently each twinkles. Jupiter should be steady like a rock, but Regulus should be twinkling away due to turbulence in the atmosphere.
Throughout this spring Jupiter and Venus are going to slowly approach each other. Now they are far apart, but by late June these two planets will come together in a close and spectacular conjunction.
March 7: One hour after sunset look to the west to see ruddy Mars below brilliant Venus.
March 20: Spring in the northern hemisphere begins at 4:45 MDT, when the sun crosses the celestial equator.
March 21: The slender crescent moon appears next to Mars after sunset.
March 22: This should be a great sight: the crescent has grown in size and has slid upward next to Venus.
Valentine’s Day on Churyumov-Gerasimenko
On Valentine’s Day, the Rosetta spacecraft dipped down low over the comet 67P/Churyumov-Gerasimenko, reaching some five miles above its surface. Considering that this rotating comet shaped like a rubber ducky is only about 2.5 miles long, it was a pretty dangerous and gutsy maneuver.
It produced an amazing image of this old and dark leftover from the birth of the solar system. The image has a resolution of perhaps two feet, which means we could see a person like the Little Prince walking across the surface. The operators were hoping they might find the now quiet lander, Philae, but it didn’t show up in the photo. What they find is a large flat area, which looks like a dried lake bed, in the upper left-hand portion of the picture. But, of course, there couldn’t have been an open body of water on this tiny, cold objet. It is probably the remnant of gas escaping ice under the surface, which left behind fine dust. Even with its very weak gravity the dust could flow around the surface and fill in a low spot. Note that the smooth area stops on the left just like water at a shoreline. No one expected something like this on a comet.
Below the flat area look for several circular features that look like impact craters. These are probably vents on the surface where gas escapes the comet when it comes close to the sun. They should start getting active, spewing forth jets of gas in the next few months.
One of the four telescopes known as “The Very Large Telescope” on Cerro Paranal in the Atacama desert of Chile has imaged the nebula known as “God’s Hand”. Each of these telescopes has a diameter of 8.2 meters. The nebula is a cometary globule, although it has nothing in common with comets. This one is 1.5 light years across, which would engulf our solar system. These globules appear completely dark, as they are made of very cold gas and dust that block the light of stars behind them. These are places where stars are born. As the cloud contracts under its own gravity and heats up, new stars will be formed. Then planets and things like comets will appear around some of them. This cometary globule was probably a spherical cloud, but it was disfigured by a nearby supernova explosion, and acquired this clumpy and irregular shape. A tail of gas, not seen in the image, extends down from the face for a distance of eight light years.
The “biggest discovery in decades” is now in tatters
Perhaps you remember a column I wrote last year in April. Well, maybe it’s better if you don’t remember. Anyhow, this is now the time for honesty and transparency.
This is what I wrote: “On March 17 the newspapers and TV stations announced the discovery of the influence of gravity waves on the early universe. This is a discovery that may rank with the discovery of dark energy or background radiation of the universe, and, if confirmed, should result in a Nobel Prize. I shall try to explain these new findings because they have such amazing philosophical and even theological implications. These are difficult ideas, and I hope I can succeed. Basically the news that lit up switchboards around the world was that a team of astronomers led by John M. Kovac of the Harvard-Smithsonian Center for Astrophysics detected ripples in the cosmic background radiation. Those ripples were produced by gravitational waves when the universe was first torn apart by cosmic inflation.”
It certainly was fun for astronomers while it lasted, even though it was very difficult to explain. It was difficult to explain because it was just plain wrong. This apparent discovery of gravitational waves seemed to be the smoking gun for the theory that the infant universe experienced an epic growth spurt known as inflation when the universe was a tiny fraction of a second old. The sudden movement of all of the matter in the universe started the cosmos vibrating like a bell, producing waves of gravity. Or so it seemed. Corks were popped and visions of a Nobel Prize appeared in folks’ heads. Now this smoking gun has itself gone up in smoke, gravity waves have vanished, and researchers are nursing a hangover.
The excitement of 17 March last was short-lived. It turns out to be very hard to make a big mistake in astronomy. Fellow astronomers are always checking up on each other, often eager to spot an error. That is indeed what science is all about: “trust but verify.” Not surprising, soon after this announcement, evidence surfaced that the evidence for gravity waves was probably flawed. Dust within our galaxy may have produced a signal that imitated gravity waves. Everyone agreed that more observations at other wavelengths were needed to test the claims. Finally in September, researchers used Europe’s Planck spacecraft to show that BICEP2’s signal was entirely due to local dust. By now everyone has agreed: no cigar, certainly no Nobel Prize! Now there is a rush of different observatories on land, in the air, and in space to search for any faint, still undetected evidence of gravity waves in the early universe. Good luck!