NASA’s Search For Life: Astrobiology In The Solar System And Beyond

Why Do X-Ray Mirrors Look So Unusual?

Does the object in this image look like a mirror? Maybe not, but that’s exactly what it is! To be more precise, it’s a set of mirrors that will be used on an X-ray telescope. But why does it look nothing like the mirrors you’re familiar with? To answer that, let’s first take a step back. Let’s talk telescopes.

How does a telescope work?

The basic function of a telescope is to gather and focus light to amplify the light’s source. Astronomers have used telescopes for centuries, and there are a few different designs. Today, most telescopes use curved mirrors that magnify and focus light from distant objects onto your eye, a camera, or some other instrument. The mirrors can be made from a variety of materials, including glass or metal.

Space telescopes like the James Webb and Hubble Space Telescopes use large mirrors to focus light from some of the most distant objects in the sky. However, the mirrors must be tailored for the type and range of light the telescope is going to capture—and X-rays are especially hard to catch.

X-rays versus mirrors

X-rays tend to zip through most things. This is because X-rays have much smaller wavelengths than most other types of light. In fact, X-rays can be smaller than a single atom of almost every element. When an X-ray encounters some surfaces, it can pass right between the atoms!

Doctors use this property of X-rays to take pictures of what’s inside you. They use a beam of X-rays that mostly passes through skin and muscle but is largely blocked by denser materials, like bone. The shadow of what was blocked shows up on the film.

This tendency to pass through things includes most mirrors. If you shoot a beam of X-rays into a standard telescope, most of the light would go right through or be absorbed. The X-rays wouldn’t be focused by the mirror, and we wouldn’t be able to study them.

X-rays can bounce off a specially designed mirror, one turned on its side so that the incoming X-rays arrive almost parallel to the surface and glance off it. At this shallow angle, the space between atoms in the mirror's surface shrinks so much that X-rays can't sneak through. The light bounces off the mirror like a stone skipping on water. This type of mirror is called a grazing incidence mirror.

A metallic onion

Telescope mirrors curve so that all of the incoming light comes to the same place. Mirrors for most telescopes are based on the same 3D shape — a paraboloid. You might remember the parabola from your math classes as the cup-shaped curve. A paraboloid is a 3D version of that, spinning it around the axis, a little like the nose cone of a rocket. This turns out to be a great shape for focusing light at a point.

Mirrors for visible and infrared light and dishes for radio light use the “cup” portion of that paraboloid. For X-ray astronomy, we cut it a little differently to use the wall. Same shape, different piece. The mirrors for visible, infrared, ultraviolet, and radio telescopes look like a gently-curving cup. The X-ray mirror looks like a cylinder with very slightly angled walls.

The image below shows how different the mirrors look. On the left is one of the Chandra X-ray Observatory’s cylindrical mirrors. On the right you can see the gently curved round primary mirror for the Stratospheric Observatory for Infrared Astronomy telescope.

If we use just one grazing incidence mirror in an X-ray telescope, there would be a big hole, as shown above (left). We’d miss a lot of X-rays! Instead, our mirror makers fill in that cylinder with layers and layers of mirrors, like an onion. Then we can collect more of the X-rays that enter the telescope, giving us more light to study.

Nested mirrors like this have been used in many X-ray telescopes. Above is a close-up of the mirrors for an upcoming observatory called the X-ray Imaging and Spectroscopy Mission (XRISM, pronounced “crism”), which is a Japan Aerospace Exploration Agency (JAXA)-led international collaboration between JAXA, NASA, and the European Space Agency (ESA).

The XRISM mirror assembly uses thin, gold-coated mirrors to make them super reflective to X-rays. Each of the two assemblies has 1,624 of these layers packed in them. And each layer is so smooth that the roughest spots rise no more than one millionth of a millimeter.

Why go to all this trouble to collect this elusive light? X-rays are a great way to study the hottest and most energetic areas of the universe! For example, at the centers of certain galaxies, there are black holes that heat up gas, producing all kinds of light. The X-rays can show us light emitted by material just before it falls in.

Stay tuned to NASA Universe on Twitter and Facebook to keep up with the latest on XRISM and other X-ray observatories.

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How does the whole sleeping situation work with 0 gravity, or do sleep mid air?

Photographing Planets with the Roman Space Telescope

Nearly 100 years ago, astronomer Bernard Lyot invented the coronagraph – a device that made it possible to recreate a total solar eclipse by blocking the Sun’s light. That helped scientists study the Sun’s corona, which is the outermost part of our star’s atmosphere that’s usually hidden by bright light from its surface.

Our Nancy Grace Roman Space Telescope, now under construction, will test out a much more advanced version of the same thing. Roman’s Coronagraph Instrument will use special masks to block the glare from host stars but allow the light from dimmer, orbiting planets to filter through. It will also have self-flexing mirrors that will measure and subtract starlight automatically.

This glare-blocking prowess is important because planets can be billions of times dimmer than their host stars! Roman’s high-tech shades will help us take pictures of planets we wouldn’t be able to photograph using any other current telescopes.

Other observatories mainly use this planet-hunting method, called direct imaging, from the ground to photograph huge, bright planets called “super-Jupiters” in infrared light. These worlds can be dozens of times more massive than Jupiter, and they’re so young that they glow brightly thanks to heat left over from their formation. That glow makes them detectable in infrared light.

Roman will take advanced planet-imaging tech to space to get even higher-quality pictures. And while it’s known for being an infrared telescope, Roman will actually photograph planets in visible light, like our eyes can see. That means it will be able to see smaller, older, colder worlds orbiting close to their host stars. Roman could even snap the first-ever image of a planet like Jupiter orbiting a star like our Sun.

Astronomers would ultimately like to take pictures of planets like Earth as part of the search for potentially habitable worlds. Roman’s direct imaging efforts will move us a giant leap in that direction!

And direct imaging is just one component of Roman’s planet-hunting plans. The mission will also use a light-bending method called microlensing to find other worlds, including rogue planets that wander the galaxy untethered to any stars. Scientists also expect Roman to discover 100,000 planets as they cross in front of their host stars!

Find out more about the Nancy Grace Roman Space Telescope on Twitter and Facebook, and about the person from which the mission draws its name.

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How Big is Our Galaxy, the Milky Way?

When we talk about the enormity of the cosmos, it’s easy to toss out big numbers – but far harder to wrap our minds around just how large, how far and how numerous celestial bodies like exoplanets – planets beyond our solar system – really are.

So. How big is our Milky Way Galaxy?

We use light-time to measure the vast distances of space.

It’s the distance that light travels in a specific period of time. Also: LIGHT IS FAST, nothing travels faster than light.

How far can light travel in one second? 186,000 miles. It might look even faster in metric: 300,000 kilometers in one second. See? FAST.

How far can light travel in one minute? 11,160,000 miles. We’re moving now! Light could go around the Earth a bit more than 448 times in one minute.

Speaking of Earth, how long does it take light from the Sun to reach our planet? 8.3 minutes. (It takes 43.2 minutes for sunlight to reach Jupiter, about 484 million miles away.) Light is fast, but the distances are VAST.

In an hour, light can travel 671 million miles. We’re still light-years from the nearest exoplanet, by the way. Proxima Centauri b is 4.2 light-years away. So… how far is a light-year? 5.8 TRILLION MILES.

A trip at light speed to the very edge of our solar system – the farthest reaches of the Oort Cloud, a collection of dormant comets way, WAY out there – would take about 1.87 years.

Our galaxy contains 100 to 400 billion stars and is about 100,000 light-years across!

One of the most distant exoplanets known to us in the Milky Way is Kepler-443b. Traveling at light speed, it would take 3,000 years to get there. Or 28 billion years, going 60 mph. So, you know, far.

SPACE IS BIG.

Read more here: go.nasa.gov/2FTyhgH

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The Lagoon Nebula 

This colorful image, taken by our Hubble Space Telescope between Feb. 12 and Feb. 18, 2018 , celebrated the Earth-orbiting observatory’s 28th anniversary of viewing the heavens, giving us a window seat to the universe’s extraordinary tapestry of stellar birth and destruction.

At the center of the photo, a monster young star 200,000 times brighter than our Sun is blasting powerful ultraviolet radiation and hurricane-like stellar winds, carving out a fantasy landscape of ridges, cavities, and mountains of gas and dust.

This region epitomizes a typical, raucous stellar nursery full of birth and destruction. The clouds may look majestic and peaceful, but they are in a constant state of flux from the star’s torrent of searing radiation and high-speed particles from stellar winds. As the monster star throws off its natal cocoon of material with its powerful energy, it is suppressing star formation around it.

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Fires in the Amazon Rainforest

This natural-color image shows smoke from fires in the Amazon rainforest spreading across several states within Brazil, including Amazonas, Mato Grosso, and Rondônia. The image was collected by our VIIRS (Visible Infrared Imaging Radiometer Suite) instrument aboard the Suomi NPP satellite (a joint-partnership between NASA and the National Oceanic and Atmospheric Administration) on August 20, 2019. It’s not unusual to see fires in Brazil at this time of year, but activity in the country’s largest state, Amazonas, has been above average. Many people use fire to maintain farmland and pastures or to clear land for other purposes.

Credits: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).

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Laying the Groundwork for a New Generation of Commercial Supersonic Aircraft

Cabin crew, prepare for takeoff. Engines roar; speed increases. You sip a cold beverage as the aircraft accelerates quietly past Mach 1 or around 600 mph. There’s no indication you’re flying over land faster than the speed of sound except when you glance at your watch upon arrival and see you’ve reached your destination in half the time. You leisurely walk off the plane with ample time to explore, finish a final report or visit a familiar face. This reality is closer than you think.

We’re on a mission to help you get to where you want to go in half the time. Using our single-pilot X-59 Quiet SuperSonic Technology (QueSST) research aircraft, we will provide rule-makers the data needed to lift current bans on faster-than-sound air travel over land and help enable a new generation of commercial supersonic aircraft.

The X-59 QueSST is unique in shape. Each element of the aircraft’s design will help reduce a loud sonic boom, typically produced by conventional supersonic aircraft, to a gentle sonic thump, making it quieter for people on the ground. To prove the quiet technology works, we will fly the X-59 over select U.S. communities to gauge the public’s response to the sound.

We are working with Lockheed Martin in Palmdale, California, to manufacture the X-59 and are making significant progress, despite the pandemic.

We finished the majority of work on the wing and closed its interior, marking the halfway point on construction of the aircraft. 

The X-59 team at Lockheed Martin completed the final touches by fastening skins to the wing. A special sealant is applied so that fuel can be carried in the wings of the aircraft.

Moving at a steady pace, technicians continue to work on many parts of the aircraft simultaneously. The forebody section of the aircraft will carry the pilot and all the avionics needed to fly the aircraft.

Because of the X-59’s long nose, the pilot will rely on an eXternal Vision System (XVS), rather than a window, for forward-facing visibility. The XVS will display fused images from an advanced computing system and cameras mounted on the upper and lower part of the aircraft’s nose.

The aft part of the aircraft will hold an F414 GE engine and other critical systems. Unlike typical aircraft, the engine inlet will be located on the upper surface of the X-59 and is one of many features that will help reduce the noise heard on the ground.

Over the next several months, the team will merge all three sections together. After final assembly in 2021, the X-59 will undergo numerous tests to ensure structural integrity of the aircraft and that ¬its components work properly. First flight of the aircraft will be in 2022 and community testing will start in 2024, making way for a new market of quiet commercial supersonic aircraft.

Want to learn more about the X-59 and our mission? Visit nasa.gov/X59. 

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Solar System: Things to Know This Week

Jupiter, our solar system's largest planet, is making a good showing in night skies this month. Look for it in the southeast in each evening. With binoculars, you may be able to see the planet's four largest moons. Here are some need-to-know facts about the King of the Planets.

1. The Biggest Planet:

With a radius of 43,440.7 miles (69,911 kilometers), Jupiter is 11 times wider than Earth. If Earth were the size of a nickel, Jupiter would be about as big as a basketball.

2. Fifth in Line

Jupiter orbits our sun, and is the fifth planet from the sun at a distance of about 484 million miles (778 million km) or 5.2 Astronomical Units (AU). Earth is one AU from the sun.

3. Short Day / Long Year

One day on Jupiter takes about 10 hours (the time it takes for Jupiter to rotate or spin once). Jupiter makes a complete orbit around the sun (a year in Jovian time) in about 12 Earth years (4,333 Earth days).

4. What's Inside?

Jupiter is a gas-giant planet without a solid surface. However, the planet may have a solid, inner core about the size of Earth.

5. Atmosphere

Jupiter's atmosphere is made up mostly of hydrogen (H2) and helium (He).

6. Many Moons

Jupiter has 53 known moons, with an additional 14 moons awaiting confirmation of their discovery — a total of 67 moons.

7. Ringed World

All four giant planets in our solar system have ring systems and Jupiter is no exception. Its faint ring system was discovered in 1979 by the Voyager 1 mission. 

8. Exploring Jupiter:

Many missions have visited Jupiter and its system of moons. The Juno spacecraft is currently orbiting Jupiter.

9. Ingredients for Life?

Jupiter cannot support life as we know it. However, some of Jupiter's moons have oceans underneath their crusts that might support life.

10. Did You Know?

Jupiter's Great Red Spot is a gigantic storm (about the size of Earth) that has been raging for hundreds of years.

Discover more lists of 10 things to know about our solar system HERE.

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What did the astronauts on the International Space Station see when they looked upon the Earth from orbit in 2017? See some of the top Earth observations from the year and download these pics, as chosen by our Earth Science and Remote Sensing Unit at the Johnson Space Center in Houston.   Astronauts have used hand-held cameras to photograph the Earth for more than 55 years. Beginning with the Mercury missions in the early 1960s, astronauts have taken more than 1.5 million photographs of the Earth. Today, the International Space Station continues this tradition of Earth observation from human-tended spacecraft. Operational since November 2000, the space station is well suited for documenting Earth features. The orbiting laboratory maintains an altitude of about 250 miles above the Earth, providing an excellent stage for observing most populated areas of the world. 

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Meet Our Latest CubeSats

When the next Orbital ATK cargo mission to the International Space Station blasts off from Wallops Flight Facility in Virginia on May 20 at 5:04 a.m. EDT carrying science and supplies, the Cygnus spacecraft will also be carrying a few of our latest CubeSats.

The International Space Station is often used to deploy small satellites, a low-cost way to test technology and science techniques in space.

On board this time, for deployment later this summer, are...

The ‘Rabbit’ in the RainCube

As its name suggests, RainCube will use radar to measure rain and snowfall. CubeSats are measured in increments of 1U (A CubeSat unit, or 1U, is roughly equivalent to a 4-inch box, or 10x10x10 centimeters). The RainCube antenna has to be small enough to be crammed into a 1.5U container; the entire satellite is about as big as a cereal box.

"It's like pulling a rabbit out of a hat," said Nacer Chahat, a specialist in antenna design at our Jet Propulsion Laboratory. "Shrinking the size of the radar is a challenge for us. As space engineers, we usually have lots of volume, so building antennas packed into a small volume isn't something we're trained to do."

That small antenna will deploy in space, like an upside-down umbrella. To maintain its small size, the antenna relies on the high-frequency Ka-band wavelength – good for profiling rain and snow. Ka-band also allows for an exponential increase in sending data over long distances, making it the perfect tool for telecommunications.

Peering Into Clouds

TEMPEST-D will also study weather. Temporal Experiment for Storms and Tropical Systems – Demonstration (TEMPEST-D) has satellite technology with the potential to measure cloud and precipitation processes on a global basis. These measurements help improve understanding of Earth’s water cycle and weather predictions, particularly conditions inside storms.

TEMPEST-D millimeter-wave observations have the ability to penetrate into clouds to where precipitation initiation occurs. By measuring the evolution of clouds from the moment of the onset of precipitation, a future TEMPEST constellation mission could improve weather forecasting and improve our understanding of cloud processes, essential to understanding climate change.

Cutting Through the Noise

CubeRRT, also the size of a cereal box, will space test a small component designed to detect and filter radio frequency interference (RFI). RFI is everywhere, from cellphones, radio and TV transmissions, satellite broadcasts and other sources. You probably recognize it as that annoying static when you can’t seem to get your favorite radio station to come in clearly because another station is nearby on the dial.

The same interference that causes radio static also affects the quality of data that instruments like microwave radiometers collect. As the number of RFI-causing devices increases globally, our satellite instruments – specifically, microwave radiometers that gather data on soil moisture, meteorology, climate and more – will be more challenged in collecting high-quality data.

That’s where CubeSat Radiometer Radio frequency interference Technology (CubeRRT) comes in. The small satellite will be carrying a new technology to detect and filter any RFI the satellite encounters in real-time from space. This will reduce the amount of data that needs to be transmitted back to Earth – increasing the quality of important weather and climate measurements.

Searching the Halo of the Milky Way

Did you know that we’re still looking for half of the normal matter that makes up the universe? Scientists have taken a census of all the stars, galaxies and clusters of galaxies — and we’re coming up short, based on what we know about the early days of the cosmos.

That missing matter might be hiding in tendrils of hot gas between galaxies. Or it might be in the halos of hot gas around individual galaxies like our own Milky Way. But if it’s there, why haven’t we seen it? It could be that it’s so hot that it glows in a spectrum of X-rays we haven’t looked at before.

Image Credit: Blue Canyon Technologies

Enter HaloSat. Led by the University of Iowa, HaloSat will search the halo of the Milky Way for the emissions oxygen gives off at these very high temperatures. Most other X-ray satellites look at narrow patches of the sky and at individual sources. HaloSat will look at large swaths of the sky at a time, which will help us figure out the geometry of the halo — whether it surrounds the galaxy more like a fried egg or a sphere. Knowing the halo’s shape will in turn help us figure out the mass, which may help us discover if the universe’s missing matter is in galactic halos.

CubeSats for All

Small satellites benefit Earth and its people (us!) in multiple ways. From Earth imaging satellites that help meteorologists to predict storm strengths and direction, to satellites that focus on technology demonstrations to help determine what materials function best in a microgravity environment, the science enabled by CubeSats is diverse. 

They are also a pathway to space science for students. Our CubeSat Launch initiative (CSLI) provides access to space for small satellites developed by our Centers and programs, educational institutions and nonprofit organizations. Since the program began, more than 50 educational CubeSats have flown. In 2016, students built the first CubeSat deployed into space by an elementary school.

Learn more about CubeSats HERE. 

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