Astronomers have detected over 5,800 confirmed exoplanets. One extreme class is ultra-hot Jupiters, of particular interest because they can provide a unique window into planetary atmospheric dynamics. According to a new paper published in the journal Nature, astronomers have mapped the 3D structure of the layered atmosphere of one such ultra-hot Jupiter-size exoplanet, revealing powerful winds that create intricate weather patterns across that atmosphere. A companion paper published in the journal Astronomy and Astrophysics reported on the unexpected identification of titanium in the exoplanet's atmosphere as well.

The case of mistaken identity was quickly resolved, but scientists say it shows the need for transparency around spaceflight traffic in deep space.

On Jan. 2, the Minor Planet Center at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, announced the discovery of an unusual asteroid, designated 2018 CN41. First identified and submitted by a citizen scientist, the object’s orbit was notable: It came less than 150,000 miles (240,000 km) from Earth, closer than the orbit of the Moon. That qualified it as a near-Earth object (NEO) — one worth monitoring for its potential to someday slam into Earth.

But less than 17 hours later, the Minor Planet Center (MPC) issued an editorial notice: It was deleting 2018 CN41 from its records because, it turned out, the object was not an asteroid.

It was a car.

Lunar exploration is undergoing a renaissance. Dozens of missions, organized by multiple space agencies—and increasingly by commercial companies—are set to visit the Moon by the end of this decade. Most of these will involve small robotic spacecraft, but NASA’s ambitious Artemis program aims to return humans to the lunar surface by the middle of the decade.

There are various reasons for all this activity, including geopolitical posturing and the search for lunar resources, such as water-ice at the lunar poles, which can be extracted and turned into hydrogen and oxygen propellant for rockets. However, science is also sure to be a major beneficiary.

The Moon still has much to tell us about the origin and evolution of the Solar System. It also has scientific value as a platform for observational astronomy. //

Several types of astronomy would benefit. The most obvious is radio astronomy, which can be conducted from the side of the Moon that always faces away from Earth—the far side.

The lunar far side is permanently shielded from the radio signals generated by humans on Earth. During the lunar night, it is also protected from the Sun. These characteristics make it probably the most “radio-quiet” location in the whole solar system, as no other planet or moon has a side that permanently faces away from the Earth. It is, therefore, ideally suited for radio astronomy. //

At that time, most of the matter in the Universe, excluding the mysterious dark matter, was in the form of neutral hydrogen atoms. These emit and absorb radiation with a characteristic wavelength of 21 cm. Radio astronomers have been using this property to study hydrogen clouds in our own galaxy—the Milky Way—since the 1950s.

Because the Universe is constantly expanding, the 21 cm signal generated by hydrogen in the early Universe has been shifted to much longer wavelengths. As a result, hydrogen from the cosmic “dark ages” will appear to us with wavelengths greater than 10 m. The lunar far side may be the only place where we can study this. //

Moreover, there are craters at the lunar poles that receive no sunlight. Telescopes that observe the Universe at infrared wavelengths are very sensitive to heat and therefore have to operate at low temperatures. JWST, for example, needs a huge sun shield to protect it from the sun’s rays. On the Moon, a natural crater rim could provide this shielding for free. //

But there is also a tension here: human activities on the lunar far side may create unwanted radio interference, and plans to extract water-ice from shadowed craters might make it difficult for those same craters to be used for astronomy. As my colleagues and I recently argued, we will need to ensure that lunar locations that are uniquely valuable for astronomy are protected in this new age of lunar exploration.

astro_pettit
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4d ago
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Comet C2024-G3 taken on GMT010/12:12. It is getting really bright as it moves towards perihelion. Most definitely eye visible. Being a handful of degrees from the sun, the zodiacal light is bright enough to interfere.

Nikon Z9, Nikon 50mm f1.2 lens, 1/5th second, f1.2, ISO 3200, adjusted Photoshop, denoise, levels, gamma, EV, color.

astro_pettit
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2d ago
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Single photo with: Milkyway, Zodical light, Starlink satellites as streaks, stars as points, atmosphere on edge showing OH emission as burned umber (my favorite Crayon color), faint red upper f-region, soon to rise sun, and cities at night as streaks lit by the nearly full moon.  Taken this morning from Dragon Crew 9 vehicle port window.

Nikon Z9, Sigma 14mm f1.4 lens, 15 seconds, f1.4, ISO 3200, adjusted Photoshop, levels, contrast, gamma, color, with homemade orbital sidereal drive to compensate for orbital pitch rate (4 degrees/sec). //

astro_pettit
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3h ago
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Black/white/colored specs are from cosmic ray damaged pixels. Unfortunately, there is a firmware bug in Z9 pixel map (Nikon is aware of and is fixing w next upgrade) that prevents it from working after a large number of damaged pixels occurs; pixel map worked for a few weeks on orbit and then quit with an error so now we can not use that feature. I am taking many dark frames and will fix my images after I return to Earth.

Almost no one ever writes about the Parker Solar Probe anymore.

Sure, the spacecraft got some attention when it launched. It is, after all, the fastest moving object that humans have ever built. At its maximum speed, goosed by the gravitational pull of the Sun, the probe reaches a velocity of 430,000 miles per hour, or more than one-sixth of 1 percent the speed of light. That kind of speed would get you from New York City to Tokyo in less than a minute. //

However, the smallish probe—it masses less than a metric ton, and its scientific payload is only about 110 pounds (50 kg)—is about to make its star turn. Quite literally. On Christmas Eve, the Parker Solar Probe will make its closest approach yet to the Sun. It will come within just 3.8 million miles (6.1 million km) of the solar surface, flying into the solar atmosphere for the first time.

Yeah, it's going to get pretty hot. Scientists estimate that the probe's heat shield will endure temperatures in excess of 2,500° Fahrenheit (1,371° C) on Christmas Eve, which is pretty much the polar opposite of the North Pole. //

I spoke with the chief of science at NASA, Nicky Fox, to understand why the probe is being tortured so. Before moving to NASA headquarters, Fox was the project scientist for the Parker Solar Probe, and she explained that scientists really want to understand the origins of the solar wind.

This is the stream of charged particles that emanate from the Sun's outermost layer, the corona. Scientists have been wondering about this particular mystery for longer than half a century, Fox explained.

"Quite simply, we want to find the birthplace of the solar wind," she said.

Way back in the 1950s, before we had satellites or spacecraft to measure the Sun's properties, Parker predicted the existence of this solar wind. The scientific community was pretty skeptical about this idea—many ridiculed Parker, in fact—until the Mariner 2 mission started measuring the solar wind in 1962.

As the scientific community began to embrace Parker's theory, they wanted to know more about the solar wind, which is such a fundamental constituent of the entire Solar System. Although the solar wind is invisible to the naked eye, when you see an aurora on Earth, that's the solar wind interacting with Earth's magnetosphere in a particularly violent way.

Only it is expensive to build a spacecraft that can get to the Sun. And really difficult, too.

Now, you might naively think that it's the easiest thing in the world to send a spacecraft to the Sun. After all, it's this big and massive object in the sky, and it's got a huge gravitational field. Things should want to go there because of this attraction, and you ought to be able to toss any old thing into the sky, and it will go toward the Sun. The problem is that you don't actually want your spacecraft to fly into the Sun or be going so fast that it passes the Sun and keeps moving. So you've got to have a pretty powerful rocket to get your spacecraft in just the right orbit. //

But you can't get around the fact that to observe the origin of the solar wind, you've got to get inside the corona. Fox explained that it's like trying to understand a forest by looking in from the outside. One actually needs to go into the forest and find a clearing. However, we can't really stay inside the forest very long—because it's on fire.

So, the Parker Solar Probe had to be robust enough to get near the Sun and then back into the coldness of space. Therein lies another challenge. The spacecraft is going from this incredibly hot environment into a cold one and then back again multiple times.

"If you think about just heating and cooling any kind of material, they either go brittle and crumble, or they may go like elastic with a continual change of property," Fox said. "Obviously, with a spacecraft like this, you can't have it making a major property change. You also need something that's lightweight, and you need something that's durable."

The science instruments had to be hardened as well. As the probe flies into the Sun there's an instrument known as a Faraday cup that hangs out to measure ion and electron fluxes from the solar wind. Unique technologies were needed. The cup itself is made from sheets of Titanium-Zirconium-Molybdenum, with a melting point of about 4,260° Fahrenheit (2,349° C). Another challenge came from the electronic wiring, as normal cables would melt. So, a team at the Smithsonian Astrophysical Observatory grew sapphire crystal tubes in which to suspend the wiring, and made the wires from niobium.

Does “Pix or it didn’t happen” apply to traveling to the edge of space on a balloon-lofted solar observatory? Yes, it absolutely does.

The breathtaking views on this page come courtesy of IRIS-2, a compact imaging package that creators [Ramón García], [Miguel Angel Gomez], [David Mayo], and [Aitor Conde] recently decided to release as open source hardware. It rode to the edge of space aboard Sunrise III, a balloon-borne solar observatory designed to study solar magnetic fields and atmospheric plasma flows.

Alternative multi-APOD front page

These latest findings further support the Hubble Space Telescope's prior expansion rate measurements.

Physicists have been puzzling over conflicting observational results pertaining to the accelerating expansion rate of our Universe—a major discovery recognized by the 2011 Nobel Prize in Physics. New observational data from the James Webb Space Telescope (JWST) has confirmed that prior measurements of distances between nearby stars and galaxies made by the Hubble Space Telescope are not in error, according to a new paper published in The Astrophysical Journal. That means the discrepancy between observation and our current theoretical model of the Universe is more likely to be due to new physics.

As previously reported, the Hubble Constant is a measure of the Universe's expansion expressed in units of kilometers per second per megaparsec (Mpc). So, each second, every megaparsec of the Universe expands by a certain number of kilometers. Another way to think of this is in terms of a relatively stationary object a megaparsec away: Each second, it gets a number of kilometers more distant.

How many kilometers? That's the problem here. There are basically three methods scientists use to measure the Hubble Constant: looking at nearby objects to see how fast they are moving, gravitational waves produced by colliding black holes or neutron stars, and measuring tiny deviations in the afterglow of the Big Bang known as the Cosmic Microwave Background (CMB). However, the various methods have come up with different values. For instance, tracking distant supernovae produced a value of 73 km/s Mpc, while measurements of the CMB using the Planck satellite produced a value of 67 km/s Mpc.

Just last year, researchers made a third independent measure of the Universe's expansion by tracking the behavior of a gravitationally lensed supernova, where the distortion in space-time caused by a massive object acts as a lens to magnify an object in the background. The best fits of those models all ended up slightly below the value of the Hubble Constant derived from the CMB, with the difference being within the statistical error. Values closer to those derived from measurements of other supernovae were a considerably worse fit for the data. The method was new, with considerable uncertainties, but it did provide an independent means of getting at the Hubble Constant.

Observations in the past several years, combined with our past knowledge, basically confirmed we live in a weird and unusual part of the universe. Some of those are supported by fairly hard numbers and others are a bit more vague. The famous Drake equation would need several more factors just to cover all relevant information to explain the lack of spacefaring civilizations.

Here are a few new-ish ones, either newly discovered, or just something we didn’t realize is highly relevant in this context.

1. The Sun is not normal. It’s a type G star, this puts it in a group of stars numbering 7.6% of the Milky way. Of those it’s in the 10% most stable type G stars stars. A stable star is probably necessary for life and the factor for a suitable star is around 0.7% at this point.

2. Plate tectonics. In relatively recent times we came to realize plate tectonics are probably important for life, recycling the crust into the mantle without wrecking havoc on the surface every few million years. Of the planets in the Solar system, only Earth has suitable plate tectonics. We don’t know how common they are in the universe, but 10% is probably generous.

3. Rocky planets are typically larger than Earth, around 1.5 times Earth mass. This is relevant, because at 125% the size of Earth you can’t make an orbital chemical rocket any more. If you want a spacefaring civilization you kind of need that, at least as a stepping stone. Let’s call this one at 10%, it shouldn’t be very far off. //

4. The Solar system itself is highly unusual and will get several points. We have large planets on the outer edges and small planets closer to the star, which is only seen in about 10% of cases. Most star systems have large planets closer to the star and smaller planets outwards.

5. Solar system part two, it is unusual for a solar system to feature both rocky planets and gas gigants. Most have one or the other type of the planet, but not both. Let’s say this is another 10%, it’s probably lower but let’s put it at 10%.

6. Solar system part three, about 85% of star systems have more than one star, 15% have one star. For type G that’s a bit higher, with 56% and we can’t explain this yet. Let’s call this one 50%.

7. Solar system part four, we’re located in an unusually calm part of the galaxy. Most places have been variously zapped with X-ray bursts, supernovae or came across various other types of other cosmic horrors that would have ended any nascent life with prejudice. Let’s put this one at 10% of the galaxy being as calm as our bit, though it could be considerably less.

If you want to count the zeroes, we’re at approximately 1 in 100 billion at this point, certainly below 1 in 10 billion. Milky way has approximately 400 billion stars. Just accounting for these factors, then adding the “chance to develop life” in and some of the other stuff present in the Drake equation, pushes the probability of advanced, spacefaring civilization forming life being present in the Milky Way, to 1 planet or less. It’s probably a lot less, we rounded plenty of those estimates upwards, because it honestly didn’t matter.

Earth is rare. We know enough to state that with some certainty. We don’t know what other solutions to the Fermi paradox are also valid, but we know enough to state Earth and Solar system being total weirdos is one of them. They might well be unique to the Milky Way and possibly even rarer than that, there’s no way to know for sure.

Demand for observing time on Webb outpaces supply by a factor of nine. //

More than 600 scientists will review the proposals and select the most promising ones for time on Webb. The largest share of proposals would involve observing "high-redshift" galaxies among the first generation of galaxies that formed after the Big Bang. Galaxies this old and distant have their light stretched to longer wavelengths due to the expansion of the Universe. Research involving exoplanet atmospheres and stars and stellar populations were the second- and third-most popular science categories in this cycle.

The James Webb Space Telescope is the most powerful telescope ever put into space. As such, its helping usher in a new era of astrophysics. Astronomers can now study farther, earlier galaxies than ever before. //

As they peer into the deep, distant history of the universe, scientists are shocked to find galaxies showed in our cosmic history much sooner than scientists ever expected.

What galaxies forming earlier than scientists thought possible means for physics
Short Wave
What galaxies forming earlier than scientists thought possible means for physics
It's a galactic controversy that has astronomers around the world excited—and puzzled.

So what is it about these galaxies that is getting astronomers worked up? Not only is JWST finding galaxies forming 200-500 million years after the Big Bang, but also that they are bigger and brighter than astronomers expected. //

But much of the modeling astronomers have done up to this point has led them to believe that there wasn't enough time for galaxies to get this massive in so little time. //

In an attempt to explain the shockingly bright, highly structured—and possibly quite massive—galaxies existing so early in the timeline of the universe, a researcher has posited that the universe is roughly twice as old as previously believed. They push the age of the universe from a spry 13.8 billion years old to roughly 26.7 billion years old. //

"I think in science, if you already have a model that's simpler than that, you should stick to it—unless you have extraordinary evidence to do otherwise."

Moreno also cautions people against quickly jumping on this supposition that the universe is twice as old as previously thought. If it were true, scientists would be able to prove it through the direct observation of stars and galaxies that are older than 13.8 billion years old—the current accepted age of the universe.

No such evidence has been found.

Several types of astronomy would benefit. The most obvious is radio astronomy, which can be conducted from the side of the Moon that always faces away from Earth—the far side.

The lunar far side is permanently shielded from the radio signals generated by humans on Earth. During the lunar night, it is also protected from the Sun. These characteristics make it probably the most “radio-quiet” location in the whole solar system, as no other planet or moon has a side that permanently faces away from the Earth. It is, therefore, ideally suited for radio astronomy. //

Radio waves with wavelengths longer than about 15 m are blocked by Earth’s ionosphere. But radio waves at these wavelengths reach the Moon’s surface unimpeded. For astronomy, this is the last unexplored region of the electromagnetic spectrum, and it is best studied from the lunar far side.

Observations of the cosmos at these wavelengths come under the umbrella of “low-frequency radio astronomy.” These wavelengths are uniquely able to probe the structure of the early Universe, especially the cosmic “dark ages”—an era before the first galaxies formed.

At that time, most of the matter in the Universe, excluding the mysterious dark matter, was in the form of neutral hydrogen atoms. These emit and absorb radiation with a characteristic wavelength of 21 cm. Radio astronomers have been using this property to study hydrogen clouds in our own galaxy—the Milky Way—since the 1950s.

Because the Universe is constantly expanding, the 21 cm signal generated by hydrogen in the early Universe has been shifted to much longer wavelengths. As a result, hydrogen from the cosmic “dark ages” will appear to us with wavelengths greater than 10 m. The lunar far side may be the only place where we can study this. //

The Moon also offers opportunities for other types of astronomy as well. Astronomers have lots of experience with optical and infrared telescopes operating in free space, such as the Hubble telescope and JWST. However, the stability of the lunar surface may confer advantages for these types of instruments.

Moreover, there are craters at the lunar poles that receive no sunlight. Telescopes that observe the Universe at infrared wavelengths are very sensitive to heat and therefore have to operate at low temperatures. JWST, for example, needs a huge sun shield to protect it from the sun’s rays. On the Moon, a natural crater rim could provide this shielding for free.

This is a short-term forecast of the location and intensity of the aurora. This product is based on the OVATION model and provides a 30 to 90 minute forecast of the location and intensity of the aurora. The forecast lead time is the time it takes for the solar wind to travel from the L1 observation point to Earth.

Rocky debris caused by a NASA mission could create the first human-made meteor shower.

In Sept. 2022, NASA’s Double Asteroids Redirect Test (DART) intentionally collided with a tiny moonlet named Dimorphos, which orbited the asteroid Didymos, to test its asteroid deflection technology.

Scientists believe the crash produced over 2 million pounds of rocks and dust — and a new study suggests fragments of Dimorphos could land around Earth and Mars in 10 to 30 years, and the meteor showers could last for up to a century.

A sharp decline in sunspot activity in the 17th century has long puzzled astronomers. //

We realized that this [Kepler's] sunspot drawing should be able to tell us the location of the sunspot and indicate the solar cycle phase in 1607 as long as we managed to narrow down the observation point and time and reconstruct the tilt of the heliographic coordinates—meaning the positions of features on the Sun's surface—at that point in time.” //

German astronomer Gustav Spörer noted the steep decline in 1887 and 1889 papers, and his British colleagues, Edward and Annie Maunder, expanded on that work to study how the latitudes of sunspots changed over time. That period became known as the "Maunder Minimum." Spörer also came up with "Spörer's law," which holds that spots at the start of a cycle appear at higher latitudes in the Sun's northern hemisphere, moving to successively lower latitudes in the southern hemisphere as the cycle runs its course until a new cycle of sunspots begins in the higher latitudes.

But precisely how the solar cycle transitioned to the Maunder Minimum has been far from clear. //

"It is fascinating to see historical figures’ legacy records convey crucial scientific implications to modern scientists even centuries later," said co-author Sabrina Bechet of the Royal Observatory of Belgium. "I doubt if they could have imagined their records would benefit the scientific community much later, well after their deaths. We still have a lot to learn from these historical figures, apart from the history of science itself. In the case of Kepler, we are standing on the shoulders of a scientific giant."

Perseid meteors will streak through Earth’s atmosphere starting in mid-July. A first quarter moon won’t interfere with the shower’s peak on the mornings of August 11, 12 and 13.

It is about 3,000 light-years from Earth, but it can be witnessed with the naked eye. //

NASA predicts a nova will occur sometime this summer, about 3,000 light-years from Earth, but it can be witnessed with the naked eye.

The nova reoccurs once every 80 years. //

The nova should happen in a dark spot among the seven stars of Corona Borealis, known as the Northern Crown.

The dark spot contains “two stars that are bound to and in orbit around each other,” known as T Coronae Borealis or T CrB. NASA nicknamed it the Blaze Star:

Scientists carried out a survey of five million distant solar systems with the help of 'neural network' algorithms and it took an interesting turn when they found nearly 60 stars surrounded by what appeared as "giant alien power plants."

Among the 60 stars, seven of them - which were M-dwarf stars and ranged between 60 per cent and 8 per cent the size of the Sun - were seen releasing high infrared 'heat signatures,' as per the astronomers. //

While these structures are named for Freeman Dyson, a physicist and mathematician who proposed the building of a Dyson sphere to contain and capture all of a star's energy output, the concept actually goes back to a 1937 novel, Star Maker, by author Olaf Stapledon.

But as far as this study actually having detected such structures? Color me skeptical. //

What isn't said is what other explanations might cause these mid-infrared emissions; while I'm a biologist and not a cosmologist, it seems to me that a G-sequence star like our sun, were it to be surrounded by a cloud (or clouds) of gas or dust, may well also emit such an IR signature. And that's a lot more likely than an alien civilization that would by necessity be thousands, or millions of years ahead of us, technologically. //

Cliff-Hanger
3 hours ago
Ward, I'm a little disappointed. Dyson structures mentioned and not one bad pun about vacuum cleaners sucking the energy out of the stars.