Despite being extraordinarily difficult to detect for the first time, gravitational waves can be found using plenty of different techniques. The now-famous first detection at LIGO in 2015 was just one of the various ways scientists had been looking. A new paper from researchers from Europe and the US proposes how scientists might be able to detect some more by tracking the exact position of the upcoming Uranus Orbiter and Probe (UOP).
Initially suggested by NASA’s Planetary Science and Astrobiology Decadal Survey, UOP will be the first mission to Uranus since Voyager visited the system in 1986. When it finally arrives in 2044, after a 2031 launch date, it will be almost 60 years since humanity last had an up-close look at the Uranian system.
But 13 years in transit sure is a long time. Part of that time will be spent getting a gravitational boost from Jupiter, but most will be spent coasting between planetary bodies. And that much time spent in between planets is what the paper’s authors want to utilize to do non-Uranian science.
Fraser has long been a proponent of returning to Uranus, as he explains here.Gravitational waves can disrupt the fabric of space-time, causing discernible distortions, especially over long distances. If the instruments in question are sensitive enough, the massive distance between UOP and the Earth would be a viable way to detect them.
This isn’t the first time using the distance between a spacecraft and Earth has been considered for detecting gravitational waves. Pioneer 11, Cassini, and a triangulation of Galileo, Ulysses, and Mars Orbiter all had entertained suggestions of being utilized for gravitational wave detection while on their journey to their final destinations. However, the equipment they were designed with was not sensitive enough to pick up the minute fluctuations required for an actual detection.
UOP will have the added advantages of decades of improved equipment, especially communications and timing electronics, which are critical to any gravitational wave detection. It also benefits that we’ve already officially detected a gravitational wave, so we know at least what to look for.
Long distance communication is hard, as Fraser explains in this video, but it’s also key to capturing data on gravitational waves.The underlying mechanism is simple enough – consistently track the exact established position of UOP during its 13-year cruise to Uranus and cross-reference any anomalies in its position against what could be expected from known causes. These include the gravitational pull of some of the planets, or even asteroids, and solar radiation pressure on the spacecraft itself. As the authors note, some or even all of these could impact the spacecraft’s exact position; for the calculations to work effectively to find gravitational waves, better accounting for what, if any, impact they have must be completed.
But there is another potentially scientifically interesting cause of slight positional drift for the UOP: ultra-light dark matter. In theory, UOP could be used to test or even directly detect a form of dark matter known as ultra-light dark matter if it happens to exist in the solar system. Theorists have numerous models showing how it would work if it did exist. UOP could also use the same sort of exact positional calculation to contribute to that scientific research.
Best of all, UOP can do all this with literally no change to its primary functional mission – exploring the Uranian system. All that would have to be changed about the mission would be to update Earth with consistent positional data about once every 10 seconds for the duration of the 13-year trip to UOP’s final destination. Suppose there’s a chance that those more frequent check-ins with home could help detect gravitational waves or potentially dark matter. In that case, it seems well worth the consideration of the UOP mission planners – but it remains to be seen whether it will be included or not. The paper’s authors have made a persuasive argument about why it should be.
Learn More:
Zwick et al. – Bridging the micro-Hz gravitational wave gap via Doppler tracking with the Uranus Orbiter and Probe Mission: Massive black hole binaries, early universe signals and ultra-light dark matter
UT – It’s Time to Go Back to Uranus. What Questions do Scientists Have About the Ice Giants?
UT – We Could SCATTER CubeSats Around Uranus To Track How It Changes
UT – What Mission Could Detect Oceans at Uranus’ Moons?
Lead Image:
Proposed Uranus orbiter mission.
Credit – NASA Decadal Survey
The post A Mission to Uranus Could Also be a Gravitational Wave Detector appeared first on Universe Today.
Here’s an amazing and rare find: a recording of Barbra Streisand singing a popular favorite, “You’ll never know“, at age 13! And she’s already really good at that age, recognizable as La Streisand without knowing her age.
In this video, musician and music analyst Fil takes her performance of the song apart and extols her accuracy of pitch (and deviations from perfect pitch that actually improve the song), as well as her enunciation (as in the “L” in “love” at 2:23). Now you may think that a 15-minute analysis of a two-minute performance is overdoing it, but I greatly enjoyed Fil’s sonogram analysis and his acerbic remarks about autotuning, a new phenomenon that I abhor. Autotuning is ruining popular music.
The song is perhaps most famous from the Vera Lynn version from 1943. I can imagine the GIs overseas listening to it while looking at a picture of Betty Grable.
Here’s a version in which a later Barbra does a duet with the incarnation above.
I’ll add that Babs has one of the two greatest voices of our time for singing popular music. The other, of course, is Karen Carpenter. And Joni Mitchell is up there, too. I’d add Joan Baez, but she was a folk singer.
h/t: Tom
SpaceX’s Starship earned high marks today in its fourth uncrewed flight test, making significant progress in the development of a launch system that’s tasked with putting NASA astronauts on the moon by as early as 2026.
The Super Heavy booster blasted off from SpaceX’s Starbase complex in South Texas at 7:50 a.m. CT (5:50 a.m. PT), rising into the sky with 32 of its 33 methane-fueled Raptor engines blazing. Super Heavy is considered the world’s most powerful launch vehicle, with 16.7 million pounds of thrust at liftoff.
Minutes after launch, the rocket’s upper stage — known as the Ship — separated from the first stage, firing up its own set of six Raptor engines. Meanwhile, Super Heavy flew itself to a controlled splashdown in the Gulf of Mexico.
The soft splashdown marked a new achievement for Starship. During the third flight test, which took place in March, only a few of Super Heavy’s engines were able to light up again for a crucial landing burn. As a result, the booster hit the water with an uncontrolled splat.
Eventually, SpaceX plans to have the Super Heavy booster fly itself back to its base after doing its job.
The upper stage reached orbital-scale altitudes in excess of 200 kilometers (120 miles), but completing a full orbit wasn’t part of today’s plan. Instead, SpaceX aimed to have Ship make its own soft splashdown in the Indian Ocean.
Streaming video, relayed via SpaceX’s Starlink satellite network, showed the rocket’s protective skin glowing with the heat of atmospheric re-entry. Burning debris broke off from one of Ship’s control fins, damaging the camera’s lens — but the fuzzy view nevertheless confirmed that the spacecraft successfully hit the mark. That represented another advance over the third test, when the Ship broke up during its descent to the ocean.
“Despite loss of many tiles and a damaged flap, Starship made it all the way to a soft landing in the ocean!” SpaceX founder Elon Musk exulted in a posting to his X social-media platform.
NASA Administrator Bill Nelson added his congratulations on X, and noted that the successful test was a plus for the space agency’s Artemis moon program. “We are another step closer to returning humanity to the moon through Artemis — then looking onward to Mars,” he wrote.
A customized version of Ship is slated to serve as the lunar lander for Artemis 3, which would mark the first crewed mission to the moon’s surface since Apollo 17 in 1972. That mission is currently scheduled for 2026, but the timing depends in part on whether the Starship system will be ready in time.
SpaceX’s uncrewed flight tests are following a step-by-step path to get Starship in shape for a wide variety of missions — including the deployment of hundreds of Starlink satellites, point-to-point travel between spaceports on Earth, and crewed odysseys to the moon, Mars and beyond.
Starship rockets aren’t carrying payloads for these early tests. “We said it before, we’re going to say it 9,000 times: The data is the payload,” SpaceX commentator Dan Huot said during today’s flight test.
But as the development program proceeds, the envelope for the flight tests will be widened to include multi-orbit operations, payload deployments and precision touchdowns on landing pads. Before today’s test, SpaceX and the Federal Aviation Administration worked out an arrangement that’s expected to streamline the regulatory process for future flight tests.
The post Success! SpaceX’s Starship Makes a Splash in Fourth Flight Test appeared first on Universe Today.