#wfirst

Gravity is obviously pretty important. It holds your feet down to Earth so you don’t fly away into space, and (equally important) it keeps your ice cream from floating right out of your cone! We’ve learned a lot about gravity over the past few hundred years, but one of the strangest things we’ve discovered is that most of the gravity in the universe comes from an invisible source called “dark matter.” While our telescopes can’t directly see dark matter, they can help us figure out more about it thanks to a phenomenon called gravitational lensing.

The Gravity of the Situation

Anything that has mass is called matter, and all matter has gravity. Gravity pulls on everything that has mass and warps space-time, the underlying fabric of the universe. Things like llamas and doughnuts and even paper clips all warp space-time, but only a tiny bit since they aren’t very massive.

But huge clusters of galaxies are so massive that their gravity produces some pretty bizarre effects. Light always travels in a straight line, but sometimes its path is bent. When light passes close to a massive object, space-time is so warped that it curves the path the light must follow. Light that would normally be blocked by the galaxy cluster is bent around it, producing intensified — and sometimes multiple — images of the source. This process, called gravitational lensing, turns galaxy clusters into gigantic, intergalactic magnifying glasses that give us a glimpse of cosmic objects that would normally be too distant and faint for even our biggest telescopes to see.

Hubble “Sees” Dark Matter

Let’s recap — matter warps space-time. The more matter, the stronger the warp and the bigger its gravitational lensing effects. In fact, by studying “lensed” objects, we can map out the quantity and location of the unseen matter causing the distortion!

Thanks to gravitational lensing, scientists have measured the total mass of many galaxy clusters, which revealed that all the matter they can see isn’t enough to create the warping effects they observe. There’s more gravitational pull than there is visible stuff to do the pulling — a lot more! Scientists think dark matter accounts for this difference. It’s invisible to our eyes and telescopes, but it can’t hide its gravity!

The mismatch between what we see and what we know must be there may seem strange, but it’s not hard to imagine. You know that people can’t float in mid-air, so what if you saw a person appearing to do just that? You would know right away that there must be wires holding him up, even if you couldn’t see them.

Our Hubble Space Telescope observations are helping unravel the dark matter mystery. By studying gravitationally lensed galaxy clusters with Hubble, astronomers have figured out how much of the matter in the universe is “normal” and how much is “dark.” Even though normal matter makes up everything from pickles to planets, there’s about five times more dark matter in the universe than all the normal matter combined!

WFIRST Will Escalate the Search

One of our next major space telescopes, the Wide Field Infrared Survey Telescope (WFIRST), will take these gravitational lensing observations to the next level. WFIRST will be sensitive enough to use weak gravitational lensing to see how clumps of dark matter warp the appearance of distant galaxies. By observing lensing effects on this small scale, scientists will be able to fill in more of the gaps in our understanding of dark matter.

WFIRST will observe a sky area 100 times larger than Hubble does, but with the same awesome image quality. WFIRST will collect so much data in its first year that it will allow scientists to conduct in-depth studies that would have taken hundreds of years with previous telescopes.

WFIRST’s weak gravitational lensing observations will allow us to peer even further back in time than Hubble is capable of seeing. Scientists believe that the universe’s underlying dark matter structure played a major role in the formation and evolution of galaxies by attracting normal matter. Seeing the universe in its early stages will help scientists unravel how it has evolved over time and possibly provide clues to how it may continue to evolve. We don’t know what the future will hold, but WFIRST will help us find out.

This science is pretty mind-bending, even for scientists. Learn more as our current and future telescopes plan to help unlock these mysteries of the universe...

Hubble: https://www.nasa.gov/mission_pages/hubble/main/index.html WFIRST: https://wfirst.gsfc.nasa.gov/

We Have Now Reached The Limits Of The Hubble Space Telescope

“Finally, there are the wavelength limits as well. Stars emits a wide variety of light, from the ultraviolet through the optical and into the infrared. It's no coincidence that this is what Hubble was designed for: to look for light that's of the same variety and wavelengths that we know stars emit.

But this, too, is fundamentally limiting. You see, as light travels through the Universe, the fabric of space itself is expanding. This causes the light, even if it's emitted with intrinsically short wavelengths, to have its wavelength stretched by the expansion of space. By the time it arrives at our eyes, it's redshifted by a particular factor that's determined by the expansion rate of the Universe and the object's distance from us.

Hubble's wavelength range sets a fundamental limit to how far back we can see: to when the Universe is around 400 million years old, but no earlier.”

The Hubble Space Telescope, currently entering its 30th year of service, has literally revolutionized our view of the Universe. It’s shown us our faintest and most distant stars, galaxies, and galaxy clusters of all. But as far back as it’s taken us, and as spectacular as what it’s revealed, there is much, much more Universe out there, and Hubble is at its limit.

With an eye on growing cost, NASA aims for 2025 launch of next ‘great observatory’

Trump's Plan To Destroy NASA Science Laid Bare In FY2020 Budget

“The most optimistic take on the President's FY2020 proposal is this: there is bipartisan support for a United States with a strong science program across the board. WFIRST is the top priority space mission, as ranked by the National Academy of Sciences; NASA is doing what the scientific community has recommended to them as a whole by flying these flagship missions. Hubble, James Webb, and WFIRST are transformative observatories, and we can stop the President's short-sighted recommendations from becoming law.

But the budget proposal also declares that as long as he is in office, this will likely be an annual fight. A single year of missed funding or underfunding can kill a project that took decades to plan and enact. We must not lose our will. Our future and present demands that we not lose sight of a record-breaking cut to the greatest human endeavor of all: the quest to understand our existence.”

Every 10 years, NASA sends its top proposals for an independent, decadal review, where recommendations are made to decide the future of science. The pinnacle of these recommendations are the flagship missions, like Hubble, James Webb, and WFIRST. Well, the FY2020 budget has just been proposed from the President, and guess what he wants to kill?

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 Kepler space telescope is our first mission capable of identifying Earth-size planets around other stars. On Monday, June 19, 2017, scientists from many countries gathered at our Ames Research Center to talk about the latest results from the spacecraft, which include the identification of more than 200 potential new worlds! Here’s what you need to know:

We found 219 new planet candidates.

All of these worlds were found in a patch of sky near the Cygnus constellation in our Milky Way galaxy. Between 2009 and 2013, Kepler searched more than 200,000 stars in the region for orbiting planets. The 219 new planet candidates are part of the more than 4,000 planet candidates and 2,300 confirmed planets Kepler has identified to date.

Ten of these worlds are like our own.

Out of the 219 new planet candidates, 10 are possibly rocky, terrestrial worlds and orbit their star in the habitable zone – the range of distances from a star where liquid water could pool on the surface of a rocky planet.

Small planets come in two sizes.

Kepler has opened up our eyes to the existence of many small worlds. It turns out a lot of these planets are either approximately 1.5 times the size of Earth or just smaller than Neptune. The cool names given to planets of these sizes? Super Earths and mini-Neptunes.

Some of the new planets could be habitable. 

Water is a key ingredient to life as we know it. Many of the new planet candidates are likely to have small rocky cores enveloped by a thick atmosphere of hydrogen and helium, and some are thought to be ocean worlds. That doesn’t necessarily mean the oceans of these planets are full of water, but we can dream, can’t we?

Other Earths are out there.

Kepler’s survey has made it possible for us to measure the number of Earth-size habitable zone planets in our galaxy. Determining how many planets like our own that exist is the big question we’ll explore next.

The hunt for new planets continues.

Kepler continues to search for planets in different regions of space. With the launch of our Transiting Exoplanet Survey Satellite (TESS) and the James Webb Space Telescope (JWST) in 2018, we’re going to search for planets nearest the sun and measure the composition of their atmospheres. In the mid-2020s, we have our sights on taking a picture of small planets like Earth with our Wide-Field Infrared Survey Telescope (WFIRST).

*All images of planets are artist illustrations.

The First Galaxies: What We Know And What We Still Need To Learn

“As we look farther back in time, we find that younger galaxies formed stars at faster rates than galaxies do today. We can measure the star-formation rate, and find that at earlier and earlier times, it was more intense. But then we find it hits a peak when the Universe is about two billion years old. Go younger than that, and the rate goes down again.”

We’ve come incredibly far in our quest to learn how the Universe came to be the way it is today. We can see out in space for tens of billions of light years, to galaxies as they were when the Universe was only a few percent of its present age. We can see how galaxies evolve, merge and the stars inside change. And we can see to even before that, when no stars or galaxies existed at all. But how did we get from there to here? There are still plenty of gaps in the story. We’ve never seen the first stars or galaxies; we’ve never witnessed the start of cosmic reionization; we’ve never seen the star formation rate jump from zero to a real, finite number. Yet with James Webb and WFIRST on the horizon, these gaps in our knowledge may -- if we’re lucky -- all disappear.

Ask Ethan: What Surprises Might NASA's Future Space Telescopes Discover?

“One of the primary science goals for WFIRST is to survey the sky out to very large distances to look for new type Ia supernovae. These are the same events that led to the discovery of dark energy, but instead of tens or hundreds, it will collect many thousands, and out to very large distances. And what it will allow us to measure is not just the rate of expansion of the Universe, but how it's changed over time, to about ten times better precision than we can currently measure. If dark energy is different from a cosmological constant by even 1%, we'll find it. And if it's even 1% more negative than a cosmological constant's negative pressure, our Universe will end in a Big Rip.”

We know what NASA’s James Webb and WFIRST are designed for, and we know what we expect to find. James Webb will be the largest space telescope ever, focused mostly on infrared observations probing exoplanets, star-forming nebulae, galaxy evolution and the first stars and galaxies in the Universe. WFIRST will be just like Hubble, except with better instruments and 100 times the field-of-view. But the best discoveries from Hubble were things like dark energy: things we didn’t expect to find! What might some of the surprises be -- without hypothesizing radical new physics -- that these two observatories might uncover? They range from signatures of exoplanetary life to being able to possibly falsify dark matter, and they’re all incredible.