China launches two more GPS-type navigation satellites

Completing its 31st successful launch this year, China today placed two more GPS-type Beidou satellites into orbit, using a Long March 3B/G2 rocket.

The article says this is China’s 32nd launch, but that includes one failure. The leaders in the 2018 launch race:

31 China
17 SpaceX
9 Russia
8 ULA
7 Europe (Arianespace)

China has widened its lead over the U.S. in the national rankings to 31 to 26.

Russia releases video of October Soyuz launch, showing failed strap-on release

Russia has released video from the outside of its Soyuz rocket during the failed October 11 Soyuz launch, showing one of the rocket’s four strap-on boosters not releasing properly.

The key moment of the video, embedded below, is at 1:25. The booster on the left does not appear to release at its top. The article at the link says the Russians now believe that a failed sensor prevented the opening of a valve that would allow the venting of oxygen to push the booster away.

Parker begins first perihelion fly-by of Sun

It’s getting hot in here: The Parker Solar Probe has begun its first close orbital fly-by of the Sun, set to last from now until November 11.

This solar encounter encompasses the first perihelion of the mission, the point at which Parker Solar Probe is closest to the Sun. Perihelion is expected at about 10:28 p.m. EST on Nov. 5. The spacecraft will come within 15 million miles of the Sun’s surface and clock in at a top speed of 213,200 miles per hour relative to the Sun — setting new records for both closest solar approach and top heliocentric speed by a spacecraft. At perihelion, Parker Solar Probe will fly through material at about 3.6 million degrees Fahrenheit — but because material in this region is so tenuous, it doesn’t influence the temperature of the spacecraft. However, the Sun’s intense radiation heats the Sun-facing side of the spacecraft’s heat shield, called the Thermal Protection System, to about 820 F.

For several days around the Nov. 5 perihelion, Parker Solar Probe will be completely out of contact with Earth because of interference from the Sun’s overwhelming radio emissions.

The article provides some nice details about the spacecraft’s design.

October 31, 2018 Zimmerman/Pratt podcast

Today I sent a half hour with Robert Pratt of Pratt on Texas, doing two segments. In the first segment, available here, we discussed the announcement by SpaceX that it was going to do the first flight tests of its Big Falcon Rocket out of its new spaceport in Boca Chica, Texas.

In the second segment, available here, Robert allowed me to vent about the disgusting behavior of the leftist protesters during a moment of silence for those killed by an anti-Semite in Pittsburgh.

Both are worth listening to, especially the second.

First link fixed!

The vast northern plains of Mars

The vast northern plains of Mars

Cool image time! Actually, this image, found in the October image release from the high resolution camera of Mars Reconnaissance Orbiter (MRO), is not that interesting, in its own right. Context is all!

The image on the right is a small section cropped and reduced in resolution from the full image, which you can see by clicking on it. It shows one of the only interesting features in this long image strip, a small mesa sticking out all by itself in a flat featureless plain pockmarked by various small craters.

The release has no caption, though it is entitled “Northern Plains Survey.” The northern plains, while having a lot of interesting features that attract the attention of planetary scientists and thus get photographed at high resolution, is mostly featureless, at least at the resolution of the wide field survey cameras on many Mars orbiters. In order to know what is really there, they need to take high resolution images systematically, of which this image is obviously a part.

Overview image

The problem is that there is so much ground to cover. This particular image was taken of a spot in the middle of the plains just to the north of the drainage outlets from Valles Marineris, as shown by the context map to the right. The tiny white spot to the right in the middle of the blue plains north of those drainage outlets is the location of this image.

Detail area of overview map

To understand how much ground needs to be covered, to the right is a close-up of the area shown by the white box in the first image above, with red rectangles indicating where MRO has already taken images. The white cross is the subject image. As you can see, most of this immense plain has not yet been imaged. It is almost as if they threw a dart to pick this one location. Most everything around it remains unseen at high resolution. Thus, to understand the geology of this one image is hampered because the surrounding terrain remains unknown, in close detail.

Mars is a big place. It is an entire planet, with the same land surface as the Earth’s continents. It still contains many mysteries and unexplored places. It will take generations to see it all.

Early Milky Way collision uncovered by Gaia

Data from the space telescope Gaia has revealed a Milky Way merger event that occurred about 10 billion years ago.

Using the first 22 months of observations, a team of astronomers led by Amina Helmi, University of Groningen, The Netherlands, looked at seven million stars – those for which the full 3D positions and velocities are available – and found that some 30,000 of them were part of an ‘odd collection’ moving through the Milky Way. The observed stars in particular are currently passing by our solar neighbourhood.

We are so deeply embedded in this collection that its stars surround us almost completely, and so can be seen across most of the sky.

Even though they are interspersed with other stars, the stars in the collection stood out in the Gaia data because they all move along elongated trajectories in the opposite direction to the majority of the Galaxy’s other hundred billion stars, including the Sun. They also stood out in the so-called Hertzprung-Russell diagram – which is used to compare the colour and brightness of stars – indicating that they belong to a clearly distinct stellar population.

The sheer number of odd-moving stars involved intrigued Amina and her colleagues, who suspected they might have something to do with the Milky Way’s formation history and set to work to understand their origins. In the past, Amina and her research group had used computer simulations to study what happens to stars when two large galaxies merge. When she compared those to the Gaia data, the simulated results matched the observations. “The collection of stars we found with Gaia has all the properties of what you would expect from the debris of a galactic merger,” says Amina, lead author of the paper published today in Nature.

At the time, the two galaxies were both probably about the same size, approximately equivalent to the Magellanic Clouds.

Must I mention that there is some uncertainty here? The data is good, and the conclusions seem quite reasonable. At the same time, the data is still somewhat thin. We need a lot more Gaia-type telescopes mapping out the motions and positions of all the stars of the Milky Way in far more detail before the uncertainties here will shrink.

Timelapse movie of Supernova 1987A’s evolution from 1992 to 2017

Cool movie time! An astronomy graduate student in Toronto has created a movie showing the steady evolution of the shock wave from Supernova 1987A, the first supernova visible to the naked eye since the discovery of the telescope, during the past twenty-five years.

Yvette Cendes, a graduate student with the University of Toronto and the Leiden Observatory, has created a time-lapse showing the aftermath of the supernova over a 25-year period, from 1992 to 2017. The images show the shockwave expanding outward and slamming into debris that ringed the original star before its demise.

In an accompanying paper, published in the Astrophysical Journal on October 31st, Cendes and her colleagues add to the evidence that the expanding remnant is shaped—not like a ring like those of Saturn’s—but like a donut, a form known as a torus. They also confirm that the shockwave has now picked up some one thousand kilometres per second in speed. The acceleration has occurred because the expanding torus has punched through the ring of debris.

The animation, which I have embedded below the fold, uses images produced by an array radio telescopes in Australia.
» Read more

Oblique view of Hayabusa-2’s most recent landing rehearsal

Cool movie time! The Hayabusa-2 science team has released a small movie of images taken by a side-mounted camera of the spacecraft’s most recent landing rehearsal, showing the spacecraft ascend from its closest approach from an oblique angle.

I have embedded the movie from these images below the fold. As they note,

Images taken with the small monitor camera (CAM-H) during the Touchdown 1 Rehearsal 3 operation (TD1-R3). One image was captured every second from immediately after the spacecraft began to ascend (altitude 21m) on October 25, 2018 at 11:47 JST. The spacecraft was rising at about 52cm/s.

It appears the closest image was taken from about 21 meters away, about 65 feet, and gives a sense of scale. It also reveals once again how difficult that landing in January is going to be. Though this location is thought to be the smoothest spot on Ryugu, it is still littered with rocks that could cause problems.
» Read more

Shake-up in SpaceX’s Starlink satellite division

Capitalism in space: It appears that Elon Musk has done a major shake-up in SpaceX’s Starlink satellite division, firing a number of managers because he was unsatisfied with the slow pace of development.

The management shakeup followed in-fighting over pressure from Musk to speed up satellite testing schedules, one of the sources said. SpaceX’s Behrend offered no comment on the matter.

Culture was also a challenge for recent hires, a second source said. A number of the managers had been hired from nearby technology giant Microsoft, where workers were more accustomed to longer development schedules than Musk’s famously short deadlines. Another senior manager that left SpaceX was Kim Schulze, who was previously a development manager at Microsoft, one of the people said. Schulze did not respond to a request for comment.

“Rajeev wanted three more iterations of test satellites,” one of the sources said. “Elon thinks we can do the job with cheaper and simpler satellites, sooner.”

A billionaire and Chief Executive Officer of Tesla Inc, Musk is known for ambitious projects ranging from auto electrification and rocket-building to high-speed transit tunnels.

Musk’s desire for speed here actually makes very good economic sense. There are other companies developing similar internet satellite constellations, and if SpaceX’s launches late they will likely lose a significant market share.

His concern about the slow pace seems to me also justified. This technology, while cutting edge, shouldn’t require as much testing and prototype work as it appears the fired managers wanted. Better to get something working and launched and making money, introducing upgrades as you go, as SpaceX has done so successfully with its Falcon 9 rocket.

NASA decides to continue to ping Opportunity

NASA has decided to continue through January its effort to both listen and send signals to Opportunity in the hope of bringing it to life.

The 45-day deadline passed late last week. But NASA will continue active listening — a strategy that involves both sending commands to Opportunity and listening for any peeps the six-wheeled robot may make — for several more months at least, agency officials announced yesterday. “After a review of the progress of the listening campaign, NASA will continue its current strategy for attempting to make contact with the Opportunity rover for the foreseeable future,” NASA officials wrote in a mission update yesterday. “Winds could increase in the next few months at Opportunity’s location on Mars, resulting in dust being blown off the rover’s solar panels,” they added. “The agency will reassess the situation in the January 2019 time frame.”

This is exactly what the planetary scientists wanted. Their hope is that, with the beginning of dust devil season in November, the chances will then increase for removing the dust that likely covers the rover’s solar panels. It is thought that the rover has a better shot at coming back to life during this time period.

Hawaii Supreme Court rules in favor of TMT

Hawaii’s Supreme Court today upheld by a 4-1 vote the construction permits of the consortium building the Thirty Meter Telescope (TMT) on Mauna Kea.

In its own press release, the TMT consortium said that it “will move forward with fulfilling the numerous conditions and requirements of [the state’s permit] prior to the start of any construction.”

The comments by one of the the telescope’s opponents at the first link are revealing.

Kealoha Pisciotta, one of the main leaders against the telescope, said she’s doesn’t know what their next steps will be, but she’s not hopeful that more legal wrangling will help. “The court is the last bastion in democracy,” she said. “The only other option is to take to the streets. If we lose the integrity of the court, then you’re losing normal law and order, and the only other option is people have to rise up.” [emphasis mine]

Let me translate: We didn’t get our way, so we’re now going to throw another tantrum! Expect more protests and attempts to block construction. Expect the Hawaiian government, dominated almost entirely by Democrats, to fold to those protests. Expect more delays. For example, do you really think the permit process was really done?

State Department of Land and Natural Resources Chairwoman Suzanne Case said the next steps involve telescope builders submitting construction plans. The department will review the plans before issuing permission to proceed.

This was all done almost a decade earlier, and was exactly what the Supreme Court ruled on. To bring it up now suggests the state government is still quietly looking for loopholes to stop the construction, even though the public supports construction and the protesters are a decided minority.

NASA officially retires Kepler

NASA today officially retired Kepler after nine years of operations.

After nine years in deep space collecting data that indicate our sky to be filled with billions of hidden planets – more planets even than stars – NASA’s Kepler space telescope has run out of fuel needed for further science operations. NASA has decided to retire the spacecraft within its current, safe orbit, away from Earth. Kepler leaves a legacy of more than 2,600 planet discoveries from outside our solar system, many of which could be promising places for life.

Exoplanet hunting however does not end here. Unlike Hubble, astronomers and NASA planned ahead for Kepler’s demise, and this year launched TESS to continue its work, in an even more sophisticated manner.

The steep slumping wall of a Martian volcano caldera

Caldera wall

Cool image time. The Mars Reconnaissance Orbiter science team today released a nice captioned image of the steep wall of the caldera of Ascraeus Mons, the northernmost of the three giant volcanoes that lie to the east of Olympus Mons, the biggest volcano of all. The image on the right, reduced and cropped, shows that steep wall, with full image available by clicking on it. The caption from the release focuses on the fluted upper parts of the wall.

We can see chutes carved into the soft dust that has built up on the slope, with some similarities to gully landforms elsewhere on the planet.

More revealing to me is how this image reveals the slumping that is slowing eroding the caldera’s walls while also making that caldera larger. First, the plateau above the cliff shows multiple small cliffs and pit chains, all more or less parallel to the wall. This suggests that the plateau is over time breaking apart and falling into that caldera. Think of it as an avalanche in slow motion, with the upper plateau separating into chunks as sections slowly tilt down toward eventual collapse. As these chunks separate, they cause cracks to form in that plateau, and hence the parallel cliffs and strings of pits.

On the floor of the caldera we can see evidence of past chunks that did fall, piled up in a series terraces at the base of the wall. These are covered with the soft dust that dominates Martian geology. That soft dust also apparently comprises much of the wall’s materials, and almost acts like a liquid as it periodically flows down the wall, producing the chutes at the top of the wall.

The weak Martian gravity here is an important factor that we on Earth have difficulty understanding. It allows for a much steeper terrain, that also allows structurally weaker materials to hold together that would be impossible on Earth.This image gives a taste of this alien geology, on a large scale.

Curiosity resumes science operations

Though NASA has yet to announce this officially, Curiosity’s science team has made it clear that they are in the process this week of resuming full science operations.

Today was the first day of planning with the full science team since Curiosity had an anomaly on sol 2172. It has been a over a month since we last looked at the “workspace,” the region in front of the rover that the arm can reach, and there were some surprises in store for us! Before the anomaly, the rock was covered with gray-colored tailings from our failed attempt to drill the “Inverness” target, as seen in the Mastcam image from sol 2170. In the new image above, however, those tailings are now gone – and so is a lot of the dark brown soil and reddish dust. So while Curiosity has been sitting still, the winds have been moving, sweeping the workspace clean.

Those operations can also be seen in the images the rover is sending down. For the first time in almost six weeks images are arriving daily, from multiple cameras, and in large numbers.

What we yet don’t have is a detailed description outlining why it took so long to get the second computer up and running, and what they are doing, if anything, to repair the computer that produced the problems last month.

Rocket Lab adds two more satellites to its November 11 launch

Capitalism in space: Rocket Lab has signed on a new customer for its next Electron launch on November 11, adding two more satellites to the rocket’s payload.

US/New Zealand orbital launch provider Rocket Lab has signed a contract with Australian Internet of Things (IoT) start-up Fleet Space Technologies to launch two satellites from Fleet’s Proxima series, which will form the foundation of a global IoT communications constellation. The satellites have been added to the manifest for Rocket Lab’s upcoming mission, ‘It’s Business Time’, scheduled for launch on November 11 from Rocket Lab’s Launch Complex-1 on New Zealand’s Māhia Peninsula.

The Fleet satellites will join other payloads for the launch: two Spire Global Lemur-2 satellites, the Irvine CubeSat STEM Program (ICSP) IRVINE01 educational CubeSat, NABEO, a drag sail technology demonstrator designed and built by High Performance Space Structure Systems GmBH and a GeoOptics Inc. satellite, built by Tyvak Nano-Satellite Systems.

Thus, a lot will be riding on the success of this launch. It will only be the third time the company has attempted to launch Electron. So far, they have only had one successful launch.

SpaceX confirms it will do first hopper tests of BFR in Boca Chica

Capitalsm in space: SpaceX has now confirmed that it will do the first hopper flight tests of its Big Falcon Rocket (BFR) in its new spaceport facility in Boca Chica, Texas.

They hope to start these flight tests as soon as late 2019, but don’t be surprised if they don’t meet that date. It also appears that these test flights will be of the BFR’s first stage as well as its upper stage, presently dubbed the Big Falcon Spaceship (BFS). This upper stage is being designed somewhat like a space shuttle, capable of gliding into the atmosphere in order to shed speed. Unlike the shuttle, however, it will then land vertically.

In related news, the Air Force has admitted that it is having discussions with SpaceX about someday using the BFR to transport cargo from point-to-point, on the Earth.

The article at the link gives the impression that the Air Force is discussing this with multiple companies, but right now the only rocket being designed and built that would be capable of doing this at a reasonable price would be SpaceX’s BFR.

Neil Armstrong’s personal collection up for auction

Neil Armstrong’s collection of space and personal memorabilia is now being put up for auction.

The items up for auction span Armstrong’s life, from his Boy Scout cap to the Wright Flyer fragments. But other items Heritage thinks will generate interest include a small American flag that went to the moon and back with Armstrong, as well as an envelope signed by him, astronaut Buzz Aldrin and their third crewmate, Michael Collins. The envelope was considered “insurance cover” that family members could sell if the astronauts failed to return.

The auction will be held this week, on November 1st and 2nd. It is the first time material from Armstrong has ever been made available for purchase.

Parker sets new records in its flight to the Sun

The Parker Solar Probe has set two new space records, first for making the closest approach to the Sun as well as becoming the fastest spacecraft ever.

The spacecraft passed the current record of 26.55 million miles from the Sun’s surface on Oct. 29, 2018, at about 1:04 p.m. EDT, as calculated by the Parker Solar Probe team. The previous record for closest solar approach was set by the German-American Helios 2 spacecraft in April 1976. As the Parker Solar Probe mission progresses, the spacecraft will repeatedly break its own records, with a final close approach of 3.83 million miles from the Sun’s surface expected in 2024.

“It’s been just 78 days since Parker Solar Probe launched, and we’ve now come closer to our star than any other spacecraft in history,” said Project Manager Andy Driesman, from the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. “It’s a proud moment for the team, though we remain focused on our first solar encounter, which begins on Oct. 31.”

Parker Solar Probe is also expected to break the record for fastest spacecraft traveling relative to the Sun on Oct. 29 at about 10:54 p.m. EDT. The current record for heliocentric speed is 153,454 miles per hour, set by Helios 2 in April 1976.

We ain’t seen nothin’ yet. This is only the first orbit. With each later orbit the spacecraft will zip past the Sun faster, and closer.

Russia to disassemble the next Soyuz rocket scheduled for launch

In order to make sure it was assembled correctly and will separate properly, Russian engineers plan to disassemble the four strap-on boosters of the next scheduled Soyuz rocket and then put it back together for its November launch.

I wonder however if they are studying this assembly process to figure out why the manned Soyuz rocket that failed on October 11 was assembled badly so that they can revise that process. It sounds like they are merely checking to make sure the rocket is put together right, without figuring out what went wrong.

IAU once again sticks it to an American scientist, devaluing Edwin Hubble

In what is already seen by many scientists as an inappropriate action, the International Astronomical Union (IAU) this week voted to change the name of Hubble’s Law to the Hubble-Lemaître Law.

Hubble’s Law, a cornerstone of cosmology that describes the expanding universe, should now be called the Hubble-Lemaître Law, following a vote by the members of the International Astronomical Union (IAU), the same organization that revoked Pluto’s status as a planet. The change is designed to redress the historical neglect of Georges Lemaître, a Belgian astronomer and priest who in 1927 discovered the expanding universe—which also suggests a big bang. Lemaître published his ideas 2 years before U.S. astronomer Edwin Hubble described his observations that galaxies farther from the Milky Way recede faster.

There are so many things about this that are wrong it is hard to keep count. First, the IAU was never given the right to change the name of a scientific concept. It’s original job was merely to systemize the naming of astronomical objects, and that alone.

Second, it appears to be based on a misunderstanding of basic science.

The resolution has also come under fire for confusing two different issues: the expansion of the universe and the distance-velocity relation for galaxies, which is also known as the Hubble constant. Hubble never claimed to have discovered cosmic expansion, but did do much of observing work to nail down how fast the universe was expanding. “If the law is about the empirical relationship, it should be Hubble’s Law,” Kragh says. “If it is about cosmic expansion, it should be Lemaître’s Law.”

Third, it relies on bad history.

The text of the IAU resolution, circulated to members ahead of the vote, asserts that Hubble and Lemaître met in 1928, at an IAU general assembly in Leiden, the Netherlands—between the publication of their two papers—and “exchanged views” about the blockbuster theory. Kragh says that meeting “almost certainly didn’t take place” and that IAU’s statement “has no foundation in documented history.”

There are other problems, including the method by which the IAU conducted its vote. The bottom line is that this organization has no business sticking its nose into this issue, and it illustrates again, as happened when it tried to push a bad definition of “planets” on the planetary community in order to devalue the discovery of Pluto by an American, that there is a strong anti-American streak within it.

The radical and ugly left reveals itself again

They’re coming for you next: At a campaign event yesterday for Marsha Blackburn, the Republican senatorial candidate for Tennessee, leftist protesters once again revealed their ugliness and dependence on smear tactics, and they did so in mere seconds.

Blackburn called for a moment of silence to mourn for the innocent people who had been killed by a anti-Semite in Pittsburgh on Saturday. Less than two seconds into that moment, a protester shouted “Marsha Blackburn is a white supremacist!” Watch below. It only lasts a minute.

This smear makes no sense. Not only is there zero evidence that Blackburn is a “white supremacist,” the slander occurs even as she is mourning the murder of Jews, something no white supremacist would do. How stupid do these leftist protesters really think people are? This isn’t going to convince anyone, and if anything, it reveals the bigoted hate-filled mentality of this protester.

It also offends the sensibility every ordinary person nationwide who watches this, both conservative or liberal. No decent person would spit on the graves of the murdered Jews as this leftist protester does. And the protester is doing this in support of the Democratic candidate in an effort to defeat the Republican.

If you are undecided on who to vote for this coming election, just remember this moment. Every Democratic Party win, anywhere, will be an endorsement of this kind of behavior.

Japan launches UAE satellite

The new colonial movement: A Japanese H-2A rocket today successfully placed into orbit the United Arab Emirates first home-built satellite.

This gives Japan six launches for 2018, matching that nation’s previous high, accomplished both in 2006 and 2017.

The UAE satellite, KhalifaSat, was essentially a cubesat, and could be considered comparable to the numerous student-built cubesats that have been built and launched by universities as teaching devices.

China successfully launches Chinese/French ocean research satellite

A joint Chinese/French ocean research satellite was successfully launched by China today using its Long March 2C rocket.

The leaders in the 2018 launch race:

30 China
17 SpaceX
9 Russia
8 ULA
7 Europe (Arianespace)

China now leads the U.S. 30 to 26 in the national rankings. Its 30 launches this year smashes its previous launch high of 20 successful launches, and suggests that China is going to come close to its predicted 40 launches for 2018.

Scientists calculate Mars methane release

A new model describing how warmer weather could cause the seasonal spikes of methane on Mars matches the data from Curiosity in Gale Crater.

Moores and his colleagues analysed how methane might seep upwards through cracks and fissures in the Martian soil until it enters the atmosphere. Warming the soil could allow the gas to leak into the air, their calculations show. Seasons on Mars are complex, especially at Curiosity’s location so close to the planet’s equator. But the highest methane levels do appear just after the warmest time of the year, suggesting that heat spreading downward allows more of the gas to be released.

The amount of gas that the scientists estimate is entering the atmosphere is a good match for the measurements Curiosity has made at Gale crater, Moores told the American Astronomical Society’s Division for Planetary Sciences meeting in Knoxville, Tennessee. The methane’s ultimate source is still a mystery. But the work could help to explain the gas’s seasonal ebb and flow, he said. [emphasis mine]

The highlighted sentence is the most important. All they have done is found that they can model the pattern of seasonal release. They still have no idea whether the methane comes from a geological or biological source, which is of course the real question.

Fast radio bursts not detected at certain radio wavelengths

In observations by two different radio telescopes operating at different radio wavelengths but looking at the same part of the sky, astronomers have found that an observed fast radio burst was not detected by one of those telescopes.

The Curtin University-led Murchison Widefield Array (MWA) and CSIRO’s Australian SKA Pathfinder (ASKAP) telescopes were searching the sky for fast radio bursts, which are exceptionally bright flashes of energy coming from deep space. These extreme events last for only a millisecond but are so bright that many astronomers initially dismissed the first recorded fast radio burst as an observational error.

In research published in the Astrophysical Journal Letters, astronomers describe how ASKAP detected several extremely bright fast radio bursts, but the MWA—which scans the sky at lower frequencies—did not see anything, even though it was pointed at the same area of sky at the same time.

Lead author Dr Marcin Sokolowski, from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR), said the fact that the fast radio bursts were not observed at lower frequencies was highly significant. “When ASKAP sees these extremely bright events and the MWA doesn’t, that tells us something really unexpected is going on; either fast radio burst sources don’t emit at low frequencies, or the signals are blocked on their way to Earth,” Dr Sokolowski said.

If blocked at these lower frequencies, this tells theorists something about the environment where the burst occurred. If instead the burst does not emit in those lower frequencies, it tells them something about the burst itself.

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