Yesterday was a really weird day in space news, and today’s Daily Space is going to touch a bit on spacecraft, sky events, and why entomologists shouldn’t look at rock fields before we do a deep dive into gamma ray bursts.
This is the Daily Space for today, Thursday, November 21, 2019. I am your host, Dr Pamela Gay, and I am here to put science in your brain.
Yesterday was a really weird day in space news, and today’s Daily Space is going to touch a bit on spacecraft, sky events, and why entomologists shouldn’t look at rock fields, before we do a deep dive into gamma ray bursts.
Elon Musk’s SpaceX has been working on developing its new Starship vehicle at facilities in Cocoa, Florida, and in Boca Chica, Texas. Conveniently, the Boca Chica facility can be seen through telephoto lenses and various folks down in South Padre Island have been streaming its construction. In particular, the LabPadre channel has done a great job catching all the excitement of this new spacecraft taking shape. Yesterday, however, things got a little too exciting during a cryogenic loading test. While filling the Starship with either liquid oxygen or liquid nitrogen, something went sideways, and the vehicle expelled pieces and gas out both ends. While the outer shell stayed standing, it is now visibly crumpled. In a statement about this incident, SpaceX stated simply: “The purpose of today’s test was to pressurize systems to the max, so the outcome was not completely unexpected. There were no injuries, nor is this a serious setback.” I have to say, I love SpaceX’s willingness to try things and expect that sometimes when you try, instead of doing, you do not. This is the part Yoda was missing. There is always a try. You just don’t know if the outcome is going to be a do or do not, and… this was a really spectacular “Do not” kind of outcome.
Speaking of trying, I’m hoping all of you will try to see tonight’s freak meteor storm. During past orbits around the sun, our planet passed through a tight knit band of debris that was left behind by an unknown comet or active asteroid. During these past passages, amazing storms of meteors – shooting stars that are actually just grains of material hitting our atmosphere – were observed to briefly light up our planet’s sky. Called the Alpha Monocerotids, this kind of an event last occurred in 1995, and now the orbits of our world and that debris have aligned again. It is predicted that between 11pm Eastern and 1am Eastern tonight there should be a storm of meteors that will have a peak rate of 7 meteors a minute sometime around 11:50pm Eastern. There is only a 32% illuminated crescent moon, so if you can see the sky, the moon shouldn’t be an issue. This storm will center on the faint and mostly ignored constellation Monocertids, which is located off the shoulder of Orion, and above Orions’s dogs and the dogstar Sirius. Here in the great plains, we’re looking at solid cloud cover, and satellite images aren’t looking good for most of North America and Europe at the moment. Those of you in the Southern Hemisphere may have better luck, and this equatorial storm will be visible pretty much wherever it is dark and clear. Hopefully someone somewhere will get some images and let us know if the 1995 storm is repeated.
There is no easy way to transition into our next story, so I’m just going to be blunt. Ohio University Entomologist William S. Rosmoser presented a conference poster at the entomology 2019 conference claiming he has found evidence of bugs and reptiles on Mars, and he is wrong. By zooming in too far on images of Martian rocks, and by tweaking contrast just so, he was able to find sets of rocks that looked reminiscent of insects, snakes, and lizards. None of these rocks were observed to move, because they are rocks, not insects, snakes, or lizards. Mars is a vast rock-strewn wasteland, and it is easy to find rocks that look like anything you want, if you look at enough images. Over the years, folks have rocks that look like Bigfoot, human faces, and so much more. And we’ve done the same thing with rocks on Bennu right here in our CosmoQuest community. And, even on Earth, people regularly find rocks that look like living things. They are still rocks. Our human mind is programmed by evolution to find patterns, and it is better see snakes that don’t exist in patterns in the rocks, then to miss the snake you are about to step on.
There could very well be fossils on Mars. I hope there are and I hope we find them. This isn’t that discovery, and I really feel bad that Dr. Rosmoser because he’s about to take a lot of grief from a lot of planetary scientists that would like him to please get off our scientific lawn. The thing is, claims like this can do a lot of harm to our ability to communicate science with the public. This can lead to weird conspiracy theories and will make it harder for us to communicate actual discoveries that may happen someday in the future. I’m frustrated by this entire situation because I don’t think Rosmoser knew ahead of time what a mess he was about to make of his inbox and mentions, I don’t any of us wanted to spend time this week saying, “It is not aliens. It is rocks.”
Moving on to today’s top science story, this week at least 7 press-releases from 7 institutes went out announcing that Gamma Ray Bursts of record energy had been spotted and studied by more than 300 astronomers. In 3 papers coming out in Nature, these scientists shared the story of long Gamma Ray Bursts GRB 190114C and GRB 180720B.
Gamma Ray Bursts come in two basic flavors: long and short. The short ones are associated with the merger of dead stars like neutron stars, while the long ones are believed to be the death throes of massive stars going supernova and forming black holes. GRBs were first discovered in the 1960s by satellites designed to monitor the Earth for nuclear tests, and it wasn’t until the late 1990s that astronomers were first able to locate the point of origin of a GRB and match the Gamma Ray Burst with an optical afterglow. This long lag between discovery in gamma-ray light and discovery in optical light comes from the difficulty of focusing gamma rays and identifying where they come from with any significant accuracy. The challenge was made all the greater by the extremely short period of time that these objects are optically bright. In the 2000s, the Swift telescope made discovery easier by combining in one spacecraft instruments to observe in gamma-rays, x-rays, and ultraviolet light. The Fermi Telescope further improved the situation with its launch a few years later. Since its launch, burst alerts have been distributed through an automated system to observers around the world, allowing anyone with a telescope to provide followup observations to GRBs, and this network has made observations of optical afterglows identification of GRBs locations a regular occurrence. Seeing them regularly, however, doesn’t mean they are well understood or that they don’t have surprises still in store for us.
On July 20, 2018 both Fermi and Swift issued an alert about a new, powerful GRB that had a maximum photon energy of 5GeV and gave off a total energy of roughly 5×10^46 Joules of energy. This is comparable to what our Sun will give off in its entire life. The optical afterglow of this object was visible for a remarkable 30 days and is among the 10 ten most powerful GRBs no matter how you try to characterize it. Study of this object allowed the processes driving the kinds of light we see to be constrained, and a paper led by Hassan Abdalla indicated that these energies may derive from some sort of a synchrotron process where magnetic fields drive electrons to accelerate to tremendous energies that in turn release powerful photons. Synchrotron processes may not be enough to explain the highest energies however, and it may be that some sort of inverse compton scattering may allow electrons to transfer even more energy to photons. Whatever is happening, this particular GRB demonstrated that that these processes can last for hours on end.
We don’t really know just how powerful a GRB can be, and what factors constrain it. In two additional papers in the same issue of Nature, astronomers focus on a January 14, 2918 GRB that had a similar total energy to the 2018 event, and had maximum energy photos that topper 1TeV – an energy that had previously only been seen in Large Hadron Collider experiments at CERN. This is a trillion times as much energy as visible light photons. European astronomers were able to get time on the Hubble Space Telescope to study the environment of the GRB and found that it occurred in the dense region right in the middle of a galaxy 5 billion light years away. According to one of the lead authors, Andrew Levan, “This is really unusual, and suggests that might be why it produced this exceptionally powerful light.” Put another way, if a giant star goes supernova in a dense environment, it may drive the event to be higher energy than would occur in isolation.
These discoveries give new inputs for theorists to work with as they try and model how massive stars explode, and how their energy interacts with their surrounds. They also highlight the importance of having telescopes programmed to automatically respond to burst alerts. The MAGIC telescope array was able to get on target less than a minute after the GRB was detected, rapidly slewing their 64ton masses to point at just the right part of the sky to measure the gamma-ray photon energies. As technology improves and as more GRBs explode near but hopefully not to near our galaxy, we can only improve our understanding of these most energetic events in our universe.
That rounds out our show for today.
Thank you all for listening. The Daily Space is produced by Susie Murph, and is a product of the Planetary Science Institute, a 501(c)3 non profit dedicated to exploring our Solar System and beyond.
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