ESA ready to begin year-long relativity experiment using salvaged satellites

esa einstein relativity galileo
The European Space Agency ran into some problems last year when it launched its fifth and sixth Galileo satellites. The satellites were supposed to be used for GPS navigation, but a faulty rocket sent them into incorrect orbits, turning the pair temporarily into very expensive space junk. The European Space Agency went to great lengths to fix their orbits, and in doing so unwittingly setup one of the best tests for Einstein’s General Theory of Relativity.

The satellites’ new orbits restore their ability to send navigational data, but the orbits are still elliptical, with each satellite rising and falling 8,500km twice each day. This change in position relative to the earth is accompanied by changes in gravity, which provides an excellent opportunity to study how gravity and time are interrelated.

Einstein’s theory of relativity says there is no fixed frame of reference in the universe. Everything that is experienced is relative to everything else. His theory predicts time passes more slowly for an object as it draws nearer to a source of gravitational pull such as the earth. In the case of the satellites, time should move more slowly as they descend towards the earth and should then speed up as they move away from the earth’s gravitational pull.

The satellites are especially suited for this year-long study because each one includes an atomic clock as part of its payload, and both are constantly being monitored by a global network of ground stations. This constant monitoring allows the researchers to test “hundreds of orbits over the course of a year,” says Javier Ventura-Traveset, ESA’s senior satnav advisor. This test is expected to produce results that are four times more accurate than the previous Gravity Probe A experiment — which also included only a single orbit.

After this unexpected experiment is complete, the ESA plans to test Einstein’s theory down to 2–3 parts per million as part of its Atomic Clock Ensemble in Space experiment. That experiment is slated to be held on the the International Space Station beginning in 2017.


Ditch the meditation app. 'Katamari Damacy Reroll' is pure gaming zen

Katamari Damacy Reroll brings the magic of the PS2 classic to Nintendo Switch and PC. With updated visuals and the same great, singular loop, Reroll stands the test of time. Katamari Damacy is the ultimate relaxation game.
Emerging Tech

We’re going to the Red Planet! All the past, present, and future missions to Mars

SpaceX isn't the only organization pining to visit the Red Planet. Here's a detailed list of all operational and planned missions to Mars, along with explanations of their objectives, spacecraft details, and mission proposals.
Home Theater

Kill your cable and switch to streaming with our painless guide

If you're going to quit cable or satellite for a streaming TV solution, you're going to want to get it right the first time. We've outlined exactly how to get started, step by step. Follow our lead, and you'll never look back.

Apple Mac users should take a bite out of these awesome games

Contrary to popular belief, there exists a bevy of popular A-list games compatible for Mac computers. Take a look at our picks for the best Mac games available for Apple fans.
Emerging Tech

The best drone photos from around the world

Most of today's drones come equipped with high-end cameras, which are quickly revolutionizing the world of aerial photography as we know it. Here are some of the best drone photos from around the world.
Emerging Tech

Are e-cigarettes safe? Here’s what the most recent science says

Ecigarettes are widely regarded and advertised as a healthier alternative to cigarettes for people who are trying to kick the smoking habit. How safe are these cigarette alternatives? We went deep into the recent scientific literature to…
Emerging Tech

Rise of the Machines: Here’s how much robots and A.I. progressed in 2018

2018 has generated no shortage of news, and the worlds of A.I. and robotics are no exception. Here are our picks for the most exciting, game changing examples of both we saw this year.
Emerging Tech

Thrill-seekers will be able to pilot themselves in a giant drone as soon as 2019

Want to hitch a ride on a giant drone? The startup Lift Aircraft is gearing up to let paying customers fly its 18-rotor giant drones over assorted scenic landscapes across the U.S.
Emerging Tech

CRISPR gene therapy regulates hunger, staves off severe obesity in mice

Researchers from UC San Francisco have demonstrated how CRISPR gene editing can be used to prevent severe obesity in mice, without making a single edit to the mouse's genome. Here's how.
Emerging Tech

Capture app saves money by 3D scanning objects using iPhone’s TrueDepth camera

Capture is a new iPhone app created by the Y Combinator-backed startup Standard Cyborg. It allows anyone to perform 3D scans of objects and share them with buddies. Here's how it works.
Emerging Tech

Sick of walking everywhere? Here are the best electric skateboards you can buy

Thanks for Kickstarter and Indiegogo, electric skateboards are carving a bigger niche than you might think. Whether you're into speed, mileage, or something a bit more stylish, here are the best electric skateboards on the market.
Emerging Tech

Parker Solar Probe captures first image from within the atmosphere of the sun

NASA has shared the first image from inside the atmosphere of the sun taken by the Parker Solar Probe. The probe made the closest ever approach to a star, gathering data which scientists have been interpreting and released this week.
Emerging Tech

Say cheese: InSight lander posts a selfie from the surface of Mars

NASA's InSight mission to Mars has commemorated its arrival by posting a selfie. The selfie is a composite of 11 different images which were taken by one of its instruments, the Instrument Deployment Camera.
Emerging Tech

Researchers create a flying wireless platform using bumblebees

Researchers at the University of Washington have come up with a novel way to create a wireless platform: using bumblebees. As mechanical drones' batteries run out too fast, the team made use of a biology-based solution using living insects.