It’s been an exciting month full of supermoons, solar eclipses, and black holes devouring stars. This week, there will be another exciting development, but one that is much easier to miss. However, it might lead to answering the greatest question ever encountered by humanity: how did we get here?
NASA will be holding a press conference Wednesday regarding the upcoming launch of their NuSTAR probe. NuSTAR, which stands for “Nuclear Spectroscopic Telescope Array,” is the first orbiting telescope of its kind, built and managed by CalTech and NASA’s Jet Propulsion Laboratory in Pasadena. It’s an X-ray telescope, which means that its mirrors are designed to reflect and focus X-rays, allowing scientists to see high-energy waves that our eyes can’t normally detect. This telescope does not emit X-rays like the machine in your doctor's office – it receives X-rays from space and reflects them using mirrors into something we can see.
NuSTAR will be using this technology to gather data about the universe that we've been unable to receive in the past. Some things in space don’t emit visible light, but do emit other signatures at a shorter wavelength. The human eye can only detect a very small portion of the wavelength spectrum, appropriately called “visible light.” Different wavelengths appear to us as different colors, something that is easily seen when a prism divides white light into a rainbow. But the spectrum of red to blue is a miniscule segment of the wavelengths out there, and NuSTAR will help us detect some of these rays that we cannot see with the naked eye.
According to CalTech, NuSTAR has a wide range of goals, but the primary focus of study will be black holes, young supernovae, relativistic jets, and other sources of high energy emissions in the Milky Way.
The first of these topics, black holes, is one of the most fashionable subjects in astrophysics today. NuSTAR will gather data that may help us understand the role that the elusive black hole plays in the universe. Black holes occur when a very large mass is crammed into a very tiny space. The resulting gravitational pull is so strong that not even light can escape. Not only are they largely an enigma, due to the obvious difficulty in detecting them, but they may hold the key to many scientific mysteries.
Black holes may play an important role in galaxy formation, because scientists have discovered supermassive black holes at the center of virtually all large galaxies, such as our own. This means that if it weren’t for Sagittarius A* (pronounced A-star), the supermassive black hole at the center of our own galaxy, the Milky Way, may never have formed, and planet earth wouldn’t have coalesced around our sun.
Black holes may even help us decipher the Big Bang itself. Physics has two widely accepted theories that describe the very massive elements of our universe (relativity) and the very minute (the Standard Model, including quantum mechanics). Those theories work perfectly, except when they are forced to interact: such as when something very massive is crammed into a very small space, like the aforementioned black hole, or during the Big Bang.
Studying black holes could help us unify those two theories. Black holes give off x-rays, but they don’t give off visible light, save for cases where a star is swallowed. NuSTAR’s X-ray could be invaluable in data gathering that could deliver a wealth of new information to scientists.
The second subject of NuSTAR’s focus, supernovae, represent the death of a star as well as the birth of new elements. When a very large star dies, it collapses in on itself, and in the hot, dense core, elements heavier than oxygen – including important elements on our own planet, like iron – are forged. Then, the dying star explodes into a supernova, spreading the heavy elements wide. The Big Bang created the three lightest elements – hydrogen, helium, and lithium – but the majority of the elements on earth, everything from carbon to the heaviest metals, were originally forged in stars and supernovae. Neil deGrasse Tyson, as usual, says it best:
The knowledge that the atoms that comprise life on earth – the atoms that make up the human body – are traceable to the crucibles that cooked light elements into heavy elements in their core under extreme temperatures and pressures. These stars – the high mass ones among them – went unstable in their later years. They collapsed and then exploded, scattering their enriched guts across the galaxy, guts made of carbon, nitrogen, oxygen, and all the fundamental ingredients of life itself. These ingredients become part of gas clouds that condense, collapse, form the next generation of solar systems: stars with orbiting planets. And those planets now have the ingredients for life itself. So that when I look up at the night sky, and I know that, yes, we are part of this universe, we are in this universe, but perhaps more important than both of those facts is that the universe is in us.
The remaining conundrums NuSTAR could help solve are relativistic jets and high-energy-emitting objects within the Milky Way. Relativistic jets are streams of plasma (ionized gas) that burst from the centers of galaxies. They are the subjects of much debate in the scientific community, and NuSTAR’s data will help scientists understand what is causing these streams. Within our own galaxy, there are other objects that emit high-frequency (short wavelength) waves like X-rays, which NuSTAR will be able to see and transcribe for awaiting scientists. Other puzzles waiting to be solved are magnetars, pulsar wind nebulae, and other phenomena that sound like something straight out of science fiction. It is amazing what we don’t know about our very own galaxy. The data gathered by the new technology of NuSTAR will reveal many of those mysteries to scientists for further study and interpretation.
NASA’s news conference will be this Wednesday, May 30 at 1:00PM EDT (10:00AM PDT). They will also be streaming the conference on Ustream. You can even participate in this press conference by sending your questions with the hashtag #asknasa on Twitter.