Earliest Evidence For Stars Smashes Hubble’s Record And Points To Dark Matter
“And most importantly, this is a glimpse into what it’s like to push back the frontiers of science. The first evidence for anything new is almost always indirect, weak, and difficult to interpret. But these unexplained signals have the power to explain what we don’t yet fully understand: how the Universe came to be the way it is today. For the first time, the Universe has given us an observational clue of where and when and what to look for. It’s up to us to take the next step.”
Earlier today, a new study was released in Nature, showcasing the earliest evidence of stars in cosmic history. The previous record was held by Hubble, which had spotted a galaxy from when the Universe was just 400 million years old: 3% of its current age. Now, indirect measurements of starlight, through the technique of radio astronomy looking for a particular hydrogen transition, has shown us evidence for a tremendous population of stars from when the Universe was between 180 and 260 million years old. This could be, truly, the first stars and galaxies of all, and it’s occurring in exactly the range that the James Webb Space Telescope will be sensitive to. Moreover, the gas that we’re observing shows signs of being far cooler than we’ve anticipated, meaning that something strange is going on, and one leading candidate is that dark matter is interacting with and cooling the gas!
This is the earliest evidence for stars in the entire Universe, and it’s just smashed Hubble’s previous record. Come get the full story right now!
World’s Largest Telescope To Finally See Stars Without Artificial Spikes
“Compared to what we can presently see with the world’s greatest observatories, the next generation of ground-based telescopes will open up a slew of new frontiers that will peel back the veil of mystery that enshrouds the unseen Universe. In addition to planets, stars, gas, plasma, black holes, galaxies, and nebulae, we’ll be looking for objects and phenomena that we’ve never seen before. Until we look, we have no way of knowing exactly what wonders the Universe has waiting for us. Owing to the clever and innovative design of the Giant Magellan Telescope, however, the objects we’ve missed due to diffraction spikes of bright, nearby stars will suddenly be revealed. There’s a whole new Universe to be observed, and this one, unique telescope will reveal what no one else can see.”
When we take images of the Universe, we are so used to seeing the sight of spikes around the stars in our own galaxy, it frequently doesn’t even occur to us that stars are near-perfect spheres, without any spikes to them at all. These are simply image artifacts created by reflecting telescopes, since they require a secondary mirror to collect and focus the light that the primary mirror reflects. These secondary mirrors are held in place by “spider arms,” which cross the plane of the mirror and block some of the light, creating these diffraction spikes. Up until now, these spikes were unavoidable, and the best we could do was using imaging techniques to try and subtract them out. But due to a brilliant design feature, the upcoming Giant Magellan Telescope, due to be the world’s largest (for a time) at 25 meters, will be the first giant reflector to image the stars exactly as they are: without these spikes at all.
It’s an observational feat that could not only revolutionize astronomy and telescope design, but will allow us to observe faint objects near bright stars, unfettered, for the very first time.
The Pillars Of Creation Haven’t Been Destroyed, After All
“Moreover, the best evidence for changes comes at the base of the pillars, indicating an evaporation time on the order of between 100,000 and 1,000,000 years. The idea that the pillars have already been destroyed has been demonstrated not to be true. It’s one of the great hopes of science that any controversial claims will be laid to rest by more and better data, and this is one situation where that has paid off in spades. Not only has there not been a supernova that’s in the process of destroying the pillars, but the pillars themselves should be robust for a long time to come.”
In 1995, NASA’s Hubble Space Telescope observed the Eagle Nebula, identifying the now-iconic pillars of creation, where newborn stars are forming inside a gas-rich, dusty region of space. Outside of those pillars, thousands of stars shine brightly, working to boil the gas off, while inside, the radiation from newly-formed stars works to boil it away from the inside. In 2007, the Spitzer Space Telescope, observing in the infrared, suggested that these pillars were blown apart thousands of years ago by a supernova, and that the light hadn’t simply reached our eyes yet. This was controversial, however, and follow-up observations would be required to know for certain. Well, the data has come in, and guess what?
The pillars of creation haven’t been destroyed after all, as the supernova seems to never have occurred. Instead of ~1,000 years, we should have hundreds of thousands of years before the pillars disappear completely. Come get the full story.
How The James Webb Space Telescope Will Deploy (In An Ideal World)
“Once the launch vehicle reaches a distance of 10,000 kilometers from Earth, just a half hour into its journey, the telescope separates from the upper stage of the rocket. At this point, JWST is free from the launch vehicle, and is now on its own, on its way to its ultimate destination. Two minutes later, the first key, but difficult step must succeed: to deploy its solar array. James Webb has a battery on board, but will only need it until the array is deployed. The thrusters will then fire, pointing the solar panels towards the Sun and orienting the observatory properly for the next step. If the array fails, the battery will last only a few hours. This step, like a great many, is a single-point-of-failure for the entire mission.”
The James Webb Space Telescope is optimized for uncovering so many secrets of the Universe, it’s impossible to list them all in a single article. From the first stars and galaxies to atmospheres around Earth-sized worlds, from the molecules present in newly-forming planets to direct images of Jupiter-sized worlds in distant solar systems, and from the pristine material left over from the Big Bang to finding the majority of water in the Universe, James Webb will answer questions that no observatory has ever addressed before. But only if it successfully launches and deploys! This takes a tremendous amount of work from vastly separate teams, all coming together without a single failure. Yet the plans have been vetted and tested as thoroughly as possible from the ground, and once the final preparatory steps are taken later this year, all that remains will be to execute the plan.
What has to happen in order for James Webb to successfully launch, deploy, and get onto the science? Find out, in-depth, today!
New Dark Matter Physics Could Solve The Expanding Universe Controversy
“If either photons, neutrinos, or some new type of dark radiation (that interacts with dark matter but not any of the normal particles) has a non-zero cross-section with dark matter, it could bias measurements of the Hubble rate to an artificially low value, but only for one type of measurement: the kind that you get from measuring these leftover relics. If interactions between dark matter and radiation are real, they might not only explain this cosmic controversy, but could be our first hint of how dark matter might directly interact with other particles. If we’re lucky, it could even give us a clue to how to finally see dark matter directly.”
One of the biggest controversies in physics today is over the expanding Universe. Despite attempts to measure the Hubble rate for nearly 100 years, we still don’t know exactly how fast the Universe expands. Two independent classes of methods, from the cosmic distance ladder and the Big Bang’s leftover relic, give two very precise and incompatible results: 73 km/s/Mpc and 67 km/s/Mpc, respectively. There’s always the possibility that one class of methods gives a biased answer, and we simply haven’t uncovered the bias. But it’s also possible that new physics is responsible, that both teams are right, and that the discrepancy is a hint of the next great leap forward in our understanding of the fundamental properties of the Universe itself.
One exciting possibility is that dark matter has a new interaction with radiation: either photons, neutrinos, or a new type of ‘dark radiation.’ Come learn more about it today!
Scientists Still Don’t Know How Fast The Universe Is Expanding
“The uncertainties on these two methods are both pretty low, but are also mutually incompatible. If the Universe has less matter and more dark energy than we presently think, the numbers on the ‘leftover relic’ method could increase to line up with the higher values. If there are errors at any stage in our distance measurements, whether from parallax, calibrations, supernova evolution, or Cepheid distances, the ‘distance ladder’ method could be artificially high. There’s also the possibility, favored by many, that the true value lies somewhere in between.”
How quickly is the fabric of space expanding? That depends on how we ask the Universe. If we look at things like the leftover glow from the Big Bang or the large-scale clustering of galaxies, we get a consistent value of 67 km/s/Mpc. But if we look at individual galaxies through a variety of methods, we get a different consistent value: 74 km/s/Mpc. The uncertainties on each method are small and do not overlap, and a potential third way of measuring this (merging neutron stars) have problems and biases all their own. A generation ago, we argued whether the Hubble constant was 50 or 100; the answer turned out to be 70. Now, we argue over whether it’s 67 or 74… or, as a few people propose, that it’s again some value in between the two.
Scientists still don’t know how fast the Universe is expanding. Here’s what the controversy is all about.
20 Gorgeous Hubble Photos That Showcase The Universe’s Beauty
“Galaxy clusters: The most massive bound structures in the Universe, these contain anywhere from a handful up to thousands of Milky Way-sized galaxies. From incredibly deep views in space to bent light by their gravity, to individual galaxies speeding through them, Hubble offers views like no other.”
It might be Christmas day here on Earth, but thanks to the Hubble Space Telescope, these views of the distant Universe are ours to treasure for all-time. The individual stars in our sky all have a glorious origin story, and will all someday die in their own spectacular fashion. These stars are formed in the most incredible nebulae, where gas races to collapse while the surrounding environs work to evaporate it away. All of this takes place inside individual galaxies, which themselves can clump and cluster together in the most massive structures the Universe has ever seen. Because of Hubble, we get to view them all.
Come explore these 20 gorgeous photos, courtesy of Hubble, that show us the Universe as we’ve never seen it before!
When Did The First Stars Appear In The Universe?
“But there’s more science to be done. Even with James Webb, we likely won’t get all the way to the very first star of all, but we’re very likely to gain a much better handle on exactly where they are and when they are. And as for the first pristine stars? The first stars verified to have nothing other than hydrogen and helium in them? If nature is kind to us, James Webb won’t only bring us the very first one of those, but will bring us many examples.
The Universe is out there, waiting for us to discover it. If we want to know the answer, all we need to do is look. As we build better observatories and take better data, our understanding of all that’s out there will only improve.”
If we look out as far as we can, there’s a big gap between what we know and what must be there. The most distant galaxy we’ve ever found is GN-z11, whose light comes from when the Universe was only 400 million years old. The next picture we have is the cosmic microwave background, emitted from when the Universe was a mere 380,000 years old. At that point, there were no stars; by time we get to 400 million years of age, we have quite large and bright galaxies. So when did the first stars actually, truly appear? It’s a question that we know an awful lot about what the answer must look like, but we’re still a few steps away from actually finding them.
Come find out all we know, and check out a video that Paul Matt Sutter and I made together explaining what we know… and what comes next!
Ask Ethan: How Much Of The Observable Universe Are We Failing To See?
“The Hubble Deep Field saw approx. 13+ Billion Light Years in one direction, so can we can assume we would see 13+ Billion in all directions? The deep field picture showed infant galaxies that are misshapen and just short of the first stars. The big bang itself lies just beyond. Does this imply that the entire universe is roughly 26+ Billion Light Years across? How is it that I have seen estimates showing we only see a small percentage of all the structure that is out there in our universe?”
When we look out at the distant Universe with our most powerful telescopes, as far as we can possibly see, what do we find? Galaxies, smaller and fainter and more and more distant, as far as we’re capable of looking. We have yet to hit the limit of where the galaxies come to an end; as far as we’ve ever been able to look, we’ve found light. Yet at some point, they must cease. There can’t be an infinite number of galaxies in a finite volume of space, and since the Universe has only had 13.8 billion years since the Big Bang, there has to be a finite number of galaxies, and a point beyond which they no longer exist. The deepest view of the Universe, the Hubble eXtreme Deep Field, revealed 5,500 galaxies in a volume comprising just 1/32,000,000th of the sky. But even that appears to be less than 10% of the galaxies out there in the Universe, despite containing galaxies much more distant than 13.8 billion light years.
How does this all make sense? And what do we know about what we haven’t yet seen? Find out on this week’s Ask Ethan!