What are Gravitational Waves?

Today, the National Science Foundation (NSF) announced the detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO), a pair of ground-based observatories. But…what are gravitational waves? Let us explain:

Gravitational waves are disturbances in space-time, the very fabric of the universe, that travel at the speed of light. The waves are emitted by any mass that is changing speed or direction. The simplest example is a binary system, where a pair of stars or compact objects (like black holes) orbit their common center of mass.

We can think of gravitational effects as curvatures in space-time. Earth’s gravity is constant and produces a static curve in space-time. A gravitational wave is a curvature that moves through space-time much like a water wave moves across the surface of a lake. It is generated only when masses are speeding up, slowing down or changing direction.

Did you know Earth also gives off gravitational waves? Earth orbits the sun, which means its direction is always changing, so it does generate gravitational waves, although extremely weak and faint.

What do we learn from these waves?

Observing gravitational waves would be a huge step forward in our understanding of the evolution of the universe, and how large-scale structures, like galaxies and galaxy clusters, are formed.

Gravitational waves can travel across the universe without being impeded by intervening dust and gas. These waves could also provide information about massive objects, such as black holes, that do not themselves emit light and would be undetectable with traditional telescopes.

Just as we need both ground-based and space-based optical telescopes, we need both kinds of gravitational wave observatories to study different wavelengths. Each type compliments the other.

Ground-based: For optical telescopes, Earth’s atmosphere prevents some wavelengths from reaching the ground and distorts the light that does.

Space-based: Telescopes in space have a clear, steady view. That said, telescopes on the ground can be much larger than anything ever launched into space, so they can capture more light from faint objects.

How does this relate to Einstein’s theory of relativity?

The direct detection of gravitational waves is the last major prediction of Einstein’s theory to be proven. Direct detection of these waves will allow scientists to test specific predictions of the theory under conditions that have not been observed to date, such as in very strong gravitational fields.

In everyday language, “theory” means something different than it does to scientists. For scientists, the word refers to a system of ideas that explains observations and experimental results through independent general principles. Isaac Newton’s theory of gravity has limitations we can measure by, say, long-term observations of the motion of the planet Mercury. Einstein’s relativity theory explains these and other measurements. We recognize that Newton’s theory is incomplete when we make sufficiently sensitive measurements. This is likely also true for relativity, and gravitational waves may help us understand where it becomes incomplete.

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NASA Astronomy Picture of the Day 2016 February 11 

LIGO Detects Gravitational Waves from Merging Black Holes 

Gravitational radiation has been directly detected. The first-ever detection was made by both facilities of the Laser Interferometer Gravitational-Wave Observatory (LIGO) in Washington and Louisiana simultaneously last September. After numerous consistency checks, the resulting 5-sigma discovery was published today. The measured gravitational waves match those expected from two large black holes merging after a death spiral in a distant galaxy, with the resulting new black hole momentarily vibrating in a rapid ringdown. 

A phenomenon predicted by Einstein, the historic discovery confirms a cornerstone of humanity’s understanding of gravity and basic physics. It is also the most direct detection of black holes ever. The featured illustration depicts the two merging black holes with the signal strength of the two detectors over 0.3 seconds superimposed across the bottom. Expected future detections by Advanced LIGO and other gravitational wave detectors may not only confirm the spectacular nature of this measurement but hold tremendous promise of giving humanity a new way to see and explore our universe.


DIY 14 Free NASA Space Travel Posters from the NASA Jet Propulsion Laboratory.

You can download these 14 Free NASA Space Travel Posters in very high resolution sizes. These free posters are perfect for a room with a retro, space, travel or adventure vibe.

Imagination is our window into the future. At NASA/JPL we strive to be bold in advancing the edge of possibility so that someday, with the help of new generations of innovators and explorers, these visions of the future can become a reality. As you look through these images of imaginative travel destinations, remember that you can be an architect of the future.

(via Girls of a Certain Age)

For a fantasy vibe, check out Persia Lou’s DIY Free and Pay Disney Travel Posters Roundup HERE.

For a more vintage vibe, check out this post: 25 Free Vintage Astronomy Printables from Remodelaholic HERE.

Today we announced big news about the Apollo 11 Command Module at our National Air and Space Museum. 

When our 3D team scanned the object, they found a set of markings that hadn’t been seen in the nearly 50 years since the historic moon landing—a discovery of astronaut graffiti. 

It includes some notes, figures and a hand-drawn calendar likely created by the crew during flight. 

An interactive 3D model, which you’ll be able to print, will be available at 3d.si.edu in June. To tide you over until then, you can see a preview in the video above. 

Read the latest chapter on this living artifact here. 

NASA SEES High School Summer Internship Program
NASA, Texas Space Grant Consortium, and The University of Texas at Austin Center for Space Research Summer Intern Program is a nationally competitive STEM program for high school students. The program provides selected interns with exposure to Earth and space research. Interns will learn how to interpret NASA satellite data while working with scientists and engineers in their chosen area of work.

(did I hear of another STEM summer program? YEP!)


NASA summer internship for High Schoolers in grades 10 and 11!

Eligible students must be:

  • American High School students in 10th and 11th grade
  • passionate about Science, Technology, Engineering, and Math

Things you will need in your application (besides providing general information about yourself)

  • A letter of recommendation from a school principal, curriculum coordinator, school counselor, science teacher or mentor 
  • A short introduction video telling us who you are, where you are from, and why you are interested in becoming a NASA high school intern.
  • Your high school transcript in PDF form
  • An essay (maximum 1000 words) on covering at least the 4 topics provided (meaning you must touch on every topic and then anything else you think is important to talk about) in PDF form

(I could not tell if the deadline is March 19th at 11:59PM or March 20th at 11:59PM, or what time zone, so I suggest submitting the application a few days early!)


ART: NASA/JPL’s Complete “Exoplanet Travel Bureau” and “Visions Of The Future” poster series

NASA is not only full of scientists and explorers, but it is also home to artistic dreamers and thinkers who, once again, took to the internet with the release of new space tourism posters.

These artists were behind last year’s “Exoplanet Travel Bureau” poster series. After its success, they’ve released the rest.

The new series, known as “Visions of the Future” includes beautiful takes on Europa, Venus, and even Earth. The first three posters of the series were published on Tuesday.

The artists work in a studio that was formed about 13 years ago at NASA’s Jet Propulsion Laboratory (JPL).

The JPL design team works closely with NASA scientists and engineers and is in tune with the latest discoveries and biggest mysteries in our solar system.

This proximity allows the artists to come up with a poster theme that revolves around planetary exploration easily.

Stars at the Galactic Center
Credit: Susan Stolovy (SSC/Caltech) et al., JPL-Caltech, NASA

Explanation: The center of our Milky Way Galaxy is hidden from the prying eyes of optical telescopes by clouds of obscuring dust and gas. But in this stunning vista, the Spitzer Space Telescope’s infrared cameras, penetrate much of the dust revealing the stars of the crowded galactic center region. A mosaic of many smaller snapshots, the detailed, false-color image shows older, cool stars in bluish hues. Reddish glowing dust clouds are associated with young, hot stars in stellar nurseries. The very center of the Milky Way was only recently found capable of forming newborn stars. The galactic center lies some 26,000 light-years away, toward the constellation Sagittarius. At that distance, this picture spans about 900 light-years.