5 Reasons Why Astronomy Is Better From The Ground Than In Space
“5.) On Earth, you can observe from anywhere you want. Once your observatory goes to space, gravity and the laws of motion fix, at any given time, exactly where that spacecraft is going to be. Plenty of astronomical curiosities can be seen from everywhere, but there are some spectacular events that require you to be in a very specific location at a particular moment in time. Occultations are an extreme example of this, where a distant, small object in the Solar System passes in front of a background star, but only for a brief instant in a particular location. Neptune’s moon Triton and New Horizons’ first post-Pluto destination, MU69, both occulted background stars, with Triton doing so regularly. Space telescopes have never been lucky enough to catch these, but thanks to mobile observatories like NASA’s SOFIA, we’ve learned how Triton’s atmosphere changes with its seasons, and we’ve even discovered a small moon around MU69! Because we don’t put all our eggs in the telescopes-in-space basket, we can do the unique science that the light arriving at our world enables.”
When it comes to astronomy, space telescopes get all the love. By flying above the atmosphere, there’s no need to wait until the atmospheric and day/night conditions are right to observe; you can look at whatever you want pretty much whenever you want, and for as long as you want. You don’t have to contend with clouds or atmospheric turbulence, and the entire electromagnetic spectrum is available to look at. We normally think of these advantages, but we hardly ever think about how much worse many things are in astronomy from space. But there are legitimately huge advantages to being on the ground, and cost doesn’t even need to be a factor to come up with five tremendous ones!
I resisted the urge to make a “groundbreaking” joke in the article, but the science is unarguable. Come learn the five reasons why astronomy is better from the ground than in space!
Sorry, Super-Earth Fans, There Are Only Three Classes Of Planet
“What’s really interesting is how the mass/radius relationship changes for these three different classes of world. Up to about double the Earth’s mass, or a size just ~25% larger than Earth’s radius, you have an opportunity to be Earth-like, with thriving life on the surface. Beyond that, you’ll have an enormous hydrogen/helium envelope, and be much more akin to Neptune, Uranus or Saturn. In other words, what we’ve been classifying as “super-Earths” aren’t anything like Earth at all, but are instead gas giant worlds, expected to be wholly inhospitable to life on their surfaces.”
Thanks to NASA’s Kepler mission, we’ve discovered literally thousands of worlds that lie beyond our own Solar System. Surprisingly, the majority of them aren’t like anything we have in our own backyard, but are somewhere in between Earth and Neptune in terms of size and mass. These worlds, usually broken into categories like “super-Earths” and/or “mini-Neptunes,” have often been viewed as new categories of planets, along with the “super-Jupiters” that we don’t see here, either. Yet these classifications are purely arbitrary, based on what we’ve seen and how we classified planets in our own neighborhood. What would we get if we classified them based on the properties that they actually possess, like mass and radius? We’d find, quite surprisingly, that there are only three classes of planet: Terran, Neptunian, and Jovian-like worlds.
Moreover, practically everything we’ve been calling a super-Earth isn’t Earth-like at all, but a Neptunian world. Come get the full story on the planets that exist in our Universe!
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!
Cancelling WFIRST Will Permanently Ruin NASA
“We absolutely cannot let this project go down without a fight. If WFIRST gets cancelled, it’s a sign that even the most important NASA project, as determined by internal, external, and independent reviewers, is subject to political whims. These projects take more than a single presidency to design, approve, build, and launch. Federal funding for these vital missions that enhance all of society must not be allowed to disappear because one human — even if it’s the president — wills it. The joys, wonder, knowledge, and benefits that come from exploring and understanding the Universe are greater than any individual.”
When it comes to NASA, there are three main functions that make up the overwhelming majority of its budget: science, exploration, and space operations. Within science, the largest and most important missions, spread across planetary science, astrophysics, Earth science and heliophysics, are known as flagship missions. According to Thomas Zurbuchen, Associate Administrator for the Science Mission Directorate of NASA, “What we learn from these flagship missions is why we study the Universe. This is civilization-scale science… If we don’t do this, we aren’t NASA.” When someone (ahem… Trump) comes in, after decades of planning, and proposes to scrap an already-designed flagship mission, it threatens to end science-as-we-know-it at NASA.
The United States must not cede leadership in the space and science arena to Japan, Russia, Europe, China, India and Canada the same way it did with the superconducting supercollider 25 years ago. This time, humanity’s capability of understanding the entire Universe is what’s at stake.
Pluto’s Surface Changes Faster Than Earth’s, And A Subsurface Ocean Is Driving It
“These mountains aren’t static and stable, but rather are temporary water-ice mountains atop a volatile, nitrogen sea. The evidence for this comes from multiple independent observations. The mountains only appear between the hilly highlands, after the edge of a basin rim, and young plains with flowing canals. These young plains occur in Pluto’s heart-shaped lobe, which itself was caused by an enormous impact crater. Only a subsurface, liquid water ocean beneath the crust could cause the uplift we then see, leaving the nitrogen to fill it in.”
In July of 2015, NASA’s New Horizons Mission arrived at Pluto, photographing the world at the highest resolution ever, with some places getting as up-close as just 80 meters (260 feet) per pixel. Not bad for a world more than 3 billion miles (5 billion kilometers) from home! What we’ve learned is breathtaking. Rather than a static, frozen world, we found one with tons of evidence for active, interior geology, as well as with a changing surface that renews itself and undergoes cycles, quite unexpectedly to many. There’s also not an enormous heart, but rather a massive, volatile-filled crater that caused Pluto to tip over at least once in its past, and may yet cause it to tip over again in the near future.
If you ever wanted to know how these distant, icy worlds come alive, there’s never been a better way to find out than in the aftermath of what New Horizons taught us!
Horrible FY2019 Budget To Gut NASA Astrophysics, Destroying Cutting-Edge Science
“WFIRST is unprecedented: it’s an observatory the size of Hubble, with the same depth, but with more than 50 times the field-of-view. It would be outfitted with two incredible instruments: a wide-field imager and a coronagraph. The imager is capable of surveying huge areas of the Universe to better understand galaxies, the intergalactic medium, dark matter, and dark energy. It would find thousands of new Type Ia supernovae out to unprecedented distances, and determine to better than 1% whether dark energy is a cosmological constant or something more exotic.”
Today, February 12th, 2018, the Trump administration unveiled their budget proposal for the Fiscal Year 2019, proposing huge cuts to a variety of departments. The biggest surprise loser, however, is NASA. Not only will the Office of Education be eliminated, along with five NASA Earth Science missions, but the flagship astrophysics mission of the 2020s, WFIRST, has been put on the chopping block. NASA gets one of these flagship missions every 10 years; Hubble was it for the 1990s, there were none for the 2000s owing to the “faster, better, cheaper” debacle, and James Webb will be the one for the 2010s. WFIRST, for years, has been the plan for the 2020s, with all the design work complete. It will measure the distant Universe, from exoplanets to galaxies to supernovae and dark energy, as never before. And unless we work with Congress to save it, we won’t have flagship-level science coming out of the 2020s. As Thomas Zurbuchen said last month, speaking for NASA:
“What we learn from these flagship missions is why we study the Universe. This is civilization-scale science… If we don’t do this, we aren’t NASA.”
Come read and understand what the horrible FY2019 budget proposal would do to NASA, and then contact your congresspeople. The time to act is now.
SpaceX’s Falcon Heavy Launch Brings Humanity One Giant Leap Closer To Mars
“There are still a slew of obstacles to overcome when it comes to taking on the challenge of Mars. But the journey to another planet was always set to begin with a single launch. There were many naysayers out there to a commercial hand in the spaceflight industry, but NASA staked their hopes of future long-distance space missions on the idea of public-private partnerships. The successful launch, deployment, and recovery of the Falcon Heavy is the proof-of-concept that settles the issue. For a cost that looks to be lower than it’s ever been, Mars is within reach.”
Have you ever dreamed of sending humans to Mars? The biggest objection has always been that the cost is prohibitive, that the development and launch of a heavy launch vehicle, as well as the cost-per-launch, would simply make this a no-go. The Saturn V’s cost of over a billion dollars (in today’s dollars) per launch is often cited as the best evidence against Mars, and NASA’s SLS isn’t much better. But the hope was always that public/private partnerships would dramatically change the story. That hope is now a reality, as the success of SpaceX’s Falcon Heavy means that enormous payloads can be sent to low-Earth orbit, geosynchronous orbit, or even beyond the gravitational pull of Earth entirely for only a tiny fraction of that price: $90 million per launch. Best of all, the boosters are recoverable, with a successful recovery happening on the very first attempt!
The game has now changed for getting to Mars. It’s time, humanity. It’s time for us to go.
Black Hole Mergers Might Actually Make Gamma-Ray Bursts, After All
“If there is a gamma-ray signal associated with black hole-black hole mergers, it heralds a revolution in physics. Black holes may have accretion disks and may often have infalling matter surrounding them, being drawn in from the interstellar medium. In the case of binary black holes, there may also be the remnants of planets and the progenitor stars floating around, as well as the potential to be housed in a messy, star-forming region. But the central black holes themselves cannot emit any radiation. If something’s emitted from their location, it must be due to the accelerated matter surrounding them. In the absence of magnetic fields anywhere near the strength of neutron stars, it’s unclear how such an energetic burst could be generated.”
In 2015, the very first black hole-black hole merger was seen by the LIGO detectors. Interestingly, the NASA Fermi team claimed the detection of a transient event well above their noise floor, beginning just 0.4 seconds after the arrival of the gravitational wave signal. On the other hand, the other gamma-ray detector in space, ESA’s Integral, not only saw nothing, but claimed the Fermi analysis was flawed. Subsequent black hole-black hole mergers showed no such signal, but they were all of far lower masses than that very first signal from September 14, 2015. Now, however, a reanalysis of the data is available from the Fermi team themselves, validating their method and indicating that, indeed, a 3-sigma result was seen during that time. It doesn’t necessarily mean that there was something real there, but it’s suggestive enough that it’s mandatory we continue to look for electromagnetic counterparts to black hole-black hole mergers.
The Universe continues to be full of surprises, and the idea that black hole mergers may make gamma-rays, after all, would be a revolutionary one! Come get the full story today.
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!
Saturn’s rotational axis is tilted, just like Earth. While Earth’s
axis is tilted at an angle of 23.4Â°, Saturn’s tilt is 26.7Â°, which is
In these pictures [1-2] you can witness the
dramatic shadows on Saturn that are cast by its rings. And in [3-4] the
shadows that are cast by Saturn on its rings. Truly epic!
Image Credit: NASA/JPL-Caltech/Space Science Institute