StarDate

The world’s largest search for ET has added more “ears” to the project. It’s using MeerKAT — an array of 64 radio telescopes in South Africa. The array can scan much more of the sky than the project’s current instruments. That allows it to listen in on many more stars.

Breakthrough Listen has been operating for three years. It uses giant radio dishes in the United States and Australia, plus a few smaller ones.

The telescopes listen for radio signals produced by civilizations in other star systems. They’re not sensitive enough to pick up routine radio broadcasts. But they could detect high-powered radar beams or similar signals. The goal is to scan a million or more nearby star systems, plus a few more-distant targets.

The project has detected a few interesting signals. But detailed study has revealed that almost all of them are either interference from radio sources on Earth, or they’re produced by stars or other astronomical objects.

MeerKAT will expand the project’s reach. It can monitor up to 64 target stars at a time, and should be sensitive to signals within about 250 light-years. Breakthrough Listen will piggyback off the work of other projects, so it’ll operate any time the telescopes are aiming at the sky.

One of the first targets is Proxima Centauri, our closest neighboring star system, about four light-years away. At least two planets orbit the star, and there could be more — potential homes for ET.
 

Script by Damond Benningfield

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Scientists are drilling deep into the ice at the south pole to learn more about some of the most elusive particles in the universe. They’ve been operating a huge observatory there for more than a decade. And they’re about to wrap up a big upgrade.

IceCube is looking for evidence of neutrinos. Stars and other objects produce huge numbers of them, and send them streaming into space at almost the speed of light. In fact, billions of neutrinos pass through every square inch of your body every second. Yet they almost never interact with other matter.

The only time they do is when they smash head on into the nucleus of an atom. That produces a flash of blue light.

IceCube uses more than 5,000 detectors buried a mile or more deep in the ice to look for those flashes. The ice blocks other types of particles and radiation, so any flashes should come from neutrinos. Scientists can trace the direction and brightness of the flashes to track their origin, and to learn something about what produced the neutrinos. That’s provided details about supermassive black holes and other sources.

The upgrade is adding about 750 detectors, which are more sensitive than the older ones. That should improve the sensitivity of IceCube by 25 percent or more.

Work is supposed to wrap up in the next few weeks — helping scientists catch a few more ghostly neutrinos.

We’ll talk about another big telescope upgrade tomorrow.
 

Script by Damond Benningfield

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A full Moon lights up this mid-winter night. On snowy ground, it adds a silvery glow to the landscape. In fact, the full Moon of February is known as the Snow Moon. And because there wasn’t much to eat at this time of year, some cultures also called it the Hunger Moon.

Every full Moon has its own name. Almost all of them are based on the traits of the time of year. So during summer, we get names like Strawberry or Corn Moon. And during fall, we have the Harvest and Hunter’s Moons.

Most of those names come from a couple of sources. One is the British Isles, from Celtic and Old English. The other is from the native cultures of North America — in particular, the Algonquin of New England.

Many of the names also applied to the months of the year. According to some sources, for example, in Old English, February was the mud month. That was either because of the messy weather, or because people made cakes for the gods that looked like they were made of mud.

The American names were popularized in the early 1900s. A book for the Boy Scouts listed many Algonquin names. And later, the names became a regular feature of the Farmer’s Almanac.

So enjoy the Snow Moon as it casts its cold light across a cold winter’s night. And it has a bright companion: Regulus, the heart of the lion. It rises below the Moon. Regulus will rise closer to the right of the Moon tomorrow night.

Script by Damond Benningfield

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The glare of the full Moon overpowers most of the stars around it. Only the brightest of stars shine through. And that’s what we have tonight. Three bright stars form a wide triangle, with the Moon along one side of it.

The star that appears closest to the Moon is Pollux, the brighter of the twins of Gemini. It’s above the Moon at nightfall. It’s a stellar giant — it’s much bigger and brighter than the Sun. It’s well past the prime of life, so it’s puffed up to giant proportions. And it’s only about 34 light-years away. The combination of size and distance makes it bright and easy to spot.

The next-closest companion star is Regulus, the leading light of Leo, the lion. It climbs into good view below the Moon by about 8 o’clock.

Regulus is a binary — two stars locked in a tight orbit around each other. The main star is much brighter and more massive than the Sun. Its companion is a white dwarf — the small, faint, dead core of a star. The system is about 80 light-years away.

The final companion is Procyon, which is well to the right of the Moon. It’s the brightest star of the little dog, so it’s known as the Little Dog Star. It, too, is a binary. And like Regulus, it consists of a star in the prime of life paired with a white dwarf. The system is among our closest neighbors — only about 11 light-years away.

Look for this trio of bright stars shining through the brilliant moonlight all night long.

Script by Damond Benningfield

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The star Castor represents one of the twins of Gemini. But it takes the business of “twinhood” to extremes. Although we see it as a single point of light, Castor actually consists of three sets of stellar twins — a total of six stars in all.

All six of them really are related. They were born from a single giant cloud of gas and dust, probably a few hundred million years ago.

Two sets of Castor’s twins are more fraternal than identical. One star in each pair is a good bit bigger, brighter, and heavier than the Sun. The other is smaller, fainter, and less massive than the Sun.

The stars in these pairs are so close together that they orbit each other in just a few days. At such close range, there’s no way for telescopes to see them as individual stars. Instead, special instruments separate the “barcodes” of the stars as they go around each other, providing details on each star.

The stars in the third pair of Castor’s twins are identical. Each star is smaller, cooler, and less massive than the Sun, and much fainter. And while the other two sets of twins are fairly close to each other, this pair is a long way away. It takes thousands of years for it to orbit the others — a set of twins that keeps its distance from its brighter siblings.

The twins of Gemini are in the east at nightfall, near the Moon. The brighter twin, Pollux, is above the Moon, with Castor about the same distance to the upper left of Pollux.

Script by Damond Benningfield

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Punxsutawney Phil carries a heavy load on his little shoulders. According to folklore, if the groundhog pops out of his burrow and sees his shadow today, there will be six more weeks of winter. If there’s no shadow, it means an early spring.

Phil has become the unofficial groundhog of Groundhog Day. He’s near the small town of Punxsutawney, Pennsylvania. His appearance is part of a day-long festival that’s been celebrated since 1887. Many other towns hold similar fetes.

There actually is a bit of truth to the legends. Crisp, sunny days often follow cold fronts — part of a pattern of continuing cold weather. Cloudy skies can be produced by warmer air pushing up from the south — perhaps the start of more spring-like patterns.

Groundhog Day is one of several commemorations of a cross-quarter day. Such days occur about half way between a solstice and an equinox. In many cultures, a cross-quarter day represented the beginning of a new season, not its middle.

In the British Isles, there were several celebrations of the February cross-quarter day. In Ireland, it began as Imbolg, which honored the goddess Brigid. Later, Christians celebrated it as Saint Brigid’s Day, honoring Ireland’s patron saint. And in other regions, it was Candlemas. People had their candles blessed by a priest, then used them to light up the rest of the year.

So keep an eye on your own skies to see if spring is nigh — or winter will maintain its icy grip.

Script by Damond Benningfield

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If you want to scoop up a lot of gold, just hang around a close pair of neutron stars. If the stars spiral together, they can produce amazing amounts of gold, silver, and other heavy elements. In fact, a merger that was seen in late 2021 produced enough to make a thousand planets as massive as Earth.

A neutron star is the tiny, ultra-dense corpse of a once-mighty star. At the end of its life, the core of such a massive star collapses. The star’s outer layers then explode as a supernova.

In December of 2021, astronomers saw the merger of two neutron stars. The stars were in a galaxy more than a billion light-years away. That was close enough to study the event in detail.

It began with a gamma-ray burst — an extremely powerful outburst of energy. It shined far brighter than the combined light of many galaxies of stars. The outburst lasted for less than a minute. That length suggested the outburst was powered by the collapse of a massive star.

But detailed analysis proved otherwise. The event was the result of the merger of two neutron stars. Much of their material splattered out into space. Temperatures were so extreme that atoms slammed together to make heavier elements — including gold and silver. The remnants of the two stars then merged to make a black hole. But many of the heavy elements escaped. Some of them may since have been incorporated into new planets — perhaps to adorn the people of future civilizations.

Script by Damond Benningfield

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The Moon is especially close to a star with a dangerous-sounding name tonight: El Nath, “the butting one.” It marks the tip of one of the horns of Taurus. It’s the bull’s second-brightest star.

El Nath is most famous for its location. It’s the closest bright star to the galactic “anticenter” — the point directly opposite the heart of the Milky Way Galaxy. So when we look in that direction, we’re looking toward the galaxy’s rim. El Nath isn’t on the rim, though. It’s about 135 light-years away, while the rim is more than 20,000 light-years farther.

El Nath is interesting for more than just its direction, though. It’s a stellar giant. It’s about five times the mass of the Sun, so even though it’s only a couple of percent the Sun’s age, it’s already past the prime of life. It’s puffed up to several times the Sun’s diameter, and it’s much hotter than the Sun. The combination makes it about 700 times brighter than the Sun.

Over the next few million years, El Nath will get even bigger and brighter. Then it will cast its outer layers into space, leaving only its hot but dense core — and the bull will lose his impressive horn.

El Nath is close to the left or lower left of the bright gibbous Moon at nightfall. Two brighter lights are in the opposite direction. Mars and Aldebaran stand to the upper right of the Moon. Mars is the brighter of the two orange lights, and stands a little higher in the sky.

Script by Damond Benningfield

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Mars and the Moon will play hide-and-seek for much of the year. The Moon will pass in front of the Red Planet four times, briefly hiding it from view. From the United States, the best of those events takes place tonight. Mars will disappear from view from Florida across Texas to southern California.

Such an event is called an occultation. That’s from a Latin word that means “to hide.” Occultations are possible because the orbits of both Mars and the Moon lie near the ecliptic, which is the Sun’s path across the sky. Both bodies wander away from the ecliptic a little, though, so most months the Moon passes within a few degrees of Mars but doesn’t cover it up.

Even when the two bodies do line up, though, it’s visible from limited regions. In part, that’s because an occultation lasts only an hour or two, so from most of Earth it happens when Mars and the Moon are below the horizon. And the Moon is much closer to us than Mars is, so most regions see the Moon pass above or below Mars — with no occultation at all.

Tonight, though, the geometry will be just right from the southern United States. The Moon will cover Mars before midnight, and the Red Planet will remain hidden for up to a couple of hours.

The rest of the country will miss out on the occultation, but will still see a beautiful sight. Mars looks like a brilliant orange star quite near the Moon throughout the night.

More about the Moon and Mars tomorrow.

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For fans of geometric shapes, the night sky is a paradise. You can connect the bright stars to make just about any shape you can think of: triangles, squares, rectangles, parallelograms, and many more.

One of the biggest and brightest of these figures is the Winter Circle or Hexagon — seven bright stars, with one more as its hub. It’s in the east and southeast as night falls now.

Its hub is Betelgeuse, the orange shoulder of Orion. It’s about halfway up the sky at nightfall, in the east-southeast. To see the circle, drop the lower right of Betelgeuse until you come to Sirius, the brightest star in the night sky. It’s in the big dog, so it’s also known as the Dog Star.

Using Betelgeuse as the center of your clock, sweep clockwise to Procyon. It is the brightest star of the little dog, so it’s known as the Little Dog Star.

Next up, in the east, are Pollux and Castor, the twins of Gemini. Capella, in Auriga the charioteer, is high above them. Then go to the right for Aldebaran, the eye of the bull. Right now, the planet Mars is close by, so it adds one more point to the circle.

Then it’s down to Rigel, Orion’s bright blue-white foot, and back to Sirius to complete the shape.

This is a good time to view this giant figure. The glare of the gibbous Moon overpowers most of the stars, but the bright lights of the Winter Circle shine through — a beautiful bit of celestial geometry for winter nights.

Script by Damond Benningfield

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