News Feeds

A team of researchers has beaten its own record for the fastest swimming soft robot, drawing inspiration from manta rays to improve their ability to control the robot's movement in the water.

A team of researchers has beaten its own record for the fastest swimming soft robot, drawing inspiration from manta rays to improve their ability to control the robot's movement in the water.

The Universe is a turbulent place. Stars are exploding, neutron stars collide, and supermassive black holes are merging. All of these things and many more create gravitational waves. As a result, the cosmos is filled with a rippling sea of gravitational vibrations. While we have been able to directly detect gravitational waves since 2016, gravitational wave astronomy is still in its infancy. We have only been able to observe the gravitational ripples of colliding stellar black holes. Even then, all we can really detect is the final gravitational chirp created in the last moments of merging.

We can, however, gather indirect evidence of the cosmic background of gravitational waves. Last year, the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) released their first observations, which were based on millisecond pulsars.

The idea behind the NANOGrav project is that pulsars emit very regular radio pulses. Millisecond pulsars are just rapidly rotating neutron stars that happen to sweep a beam of radio energy in our direction with each rotation. So, unless a neutron star experiences a rare starquake, the pulsar timing is so consistent we can use it as a cosmic clock. This means any small variation in the timing is due to a change in relative motion. As the cosmic gravitation waves ripple past a pulsar, its observed timing changes slightly. The shift isn’t large enough to observe with an individual pulsar, but it is large enough that a statistical analysis of many pulsars reveals the gravitational waves.

MeerKAT results showing pulsar correlations across the sky. Credit: Miles, et al

In the 2023 results, NANOGrav found evidence of cosmic gravitational waves but didn’t have enough data to pin down the source. But even this was a tremendous result. It took 15 years of observations just to prove the existence of these cosmic waves. Now a new observatory has released a data set, and it’s a game changer.

The MeerKat radio array is a collection of 64 antennas located in South Africa and run by the South African Radio Astronomy Observatory (SARAO). This week, SARAO released a series of papers on their results after just four and a half years. Where NANOGrav looked at 67 millisecond pulsars, MeerKAT gathered data on 83. It observed these pulsars with a similar resolution as NANOGrav, but did so in a third of the time. These results again confirm the existence of cosmic gravitational waves, but like the NANOGrav don’t confirm the origin. We still need more data to prove they are generated by binary black holes in the Milky Way. But now that we have two observational teams working on it, that necessary evidence should be found in the relatively near future.

Reference: Agazie, Gabriella, et al. “The NANOGrav 15 yr data set: Evidence for a gravitational-wave background.” The Astrophysical Journal Letters 951.1 (2023): L8.

Reference: Miles, Matthew T., et al. “The MeerKAT Pulsar Timing Array: The 4.5-year data release and the noise and stochastic signals of the millisecond pulsar population.” Monthly Notices of the Royal Astronomical Society (2024): stae2572.

Reference: Miles, Matthew T., et al. “The MeerKAT Pulsar Timing Array: The first search for gravitational waves with the MeerKAT radio telescope.” Monthly Notices of the Royal Astronomical Society (2024): stae2571.

Reference: Grunthal, Kathrin, et al. “The MeerKAT pulsar timing array: Maps of the gravitational-wave sky with the 4.5 year data release.” Monthly Notices of the Royal Astronomical Society (2024): stae2573.

The post MeerKAT Confirms the Gravitational Wave Background of the Universe in Record Time appeared first on Universe Today.

The bones of a child who died nearly 13,000 years ago suggest that the people who moved from Asia into North America at this time ate a lot of mammoth

Our television columnist Bethan Ackerley rounds up the year’s best science television, from David Attenborough (who features more than once) to Brian Cox

Research shows how exercise has other advantages in addition to the physical, whether in relation to ADHD or mental health conditions like depression and anxiety, finds Grace Wade

From horror on a North Sea oil rig to the adorable Astro Bots, our video games columnist Jacob Aron had a lot of fun in virtual worlds this year

Mark Catesby's work documents the plants and animals he saw while journeying in North America and the Caribbean

From an Earth that has become a nuclear wasteland to one threatened by extraterrestrials, there was some standout sci-fi TV in 2024. Our columnist Bethan Ackerley reveals her top five shows

Our Future Chronicles column explores an imagined history of inventions and developments yet to come. We journey to 2055, when a space elevator from the moon’s surface to near-Earth orbit was completed, opening space travel to all

Feedback takes one for the team and dips into the psychologist-turned-Youtuber's new tome, We Who Wrestle With God – only to quibble with the human biology it contains

Hindsight makes it clear that the fight against covid-19 was also a struggle against the quiet epidemic of suppressed science, says Dali L. Yang

Forget Megalopolis and Madame Web. The best science fiction films of the year were all horror-inflected, says our film columnist Simon Ings

Alternative thinking on the evolution of species is a welcome way to highlight some neglected aspects of life on Earth, but it doesn't mean Darwin was wrong

Radiation is a primary concern for long-duration human spaceflight, such as the planned trips to Mars, which are the stated goal of organizations such as NASA and SpaceX. Shielding is the standard way to protect astronauts from radiation during those flights. However, shielding is heavy and, therefore, expensive when it is launched off the Earth. What if, instead, astronauts could hitch a ride on a giant mass of shielding already in space that will take them directly to their destination? That is the basic thought behind a paper from Victor Reshetnyk and his student at Taras Shevchenko National University in Kyiv. 

They looked at data collected by NASA’s Horizons service and analyzed the orbits of over 35,000 Near Earth Objects (NEOs) for their trajectories to see if their paths would cross somewhere between the binary pairs of Earth-Venus, Earth-Mars, or Mars-Venus. If so, then in theory, they could be used as shielding from the deadly radiation astronauts would have to either suffer from or shield against on the trip.

Given the sheer amount of objects they looked at, they were bound to find some good candidates – and they did, with an estimated 525 making “fast” transfers of less than 180 days. They then further narrowed this list down to a reasonable speed during the approach to the planet they would start from – essentially to make sure that a crewed spacecraft could actually catch up to the asteroid without burning an absurd amount of fuel.

Fraser discusses how to make an asteroid a habitat.

That lowered the total amount of candidates down to 120, with the following breakdown:

• Earth -> Venus: 44
• Earth -> Mars: 17
• Mars -> Earth: 13
• Mars -> Venus: 2
• Venus -> Earth: 38
• Venus -> Mars: 6

In other words, there were plenty of options for hitching a ride. Granted, none of these would be exceptionally roomy – the largest is estimated to have a diameter of only .37 km. However, there is still plenty of room to fit a spaceship, as long as it’s not a Star Destroyer or Battleship from 40K.

Additionally, the authors found some asteroids that had more unique trajectories. Eleven had the possibility of doing “multiple” transfers, meaning they could go from Earth to Venus and then back or vice versa, but only one would do the same for the Venus to Mars trip. Two could even do a “double” transfer, meaning they could go from Earth to Venus to Mars or from Mars to Venus to Earth in less than one year. Anything beyond that wasn’t possible, though – they didn’t find any asteroids akin to an “Aldrin Cycler” that would go between the planets indefinitely on a known orbit.

Capturing an asteroid would be one way to use it for shielding – as Fraser discusses.

That’s not to say that asteroid doesn’t already exist – we might just not have found it yet. NEO Surveyor, a NASA mission designed to launch in 2028 to find 90% of all NEOs larger than 140m in diameter, could increase the number of known NEOs by an order of magnitude.

Using any of them for a massive radiation shield for a crewed mission would take much more dedicated work, though. Any such transformation is decades away at least – but the place to start is to find the right ones, and this paper contributes to that effort.

Learn More:
A.S. Kasianchuk & V. M. Reshetnyk – The search for NEOs as potential candidates for use in space missions to Venus and Mars
UT – A New Paper Shows How To Change An Asteroid Into A Space Habitat – In Just 12 Years
UT – Rubble Pile Asteroids Might be the Best Places to Build Space Habitats
UT – NASA Makes Asteroid Defense a Priority, Moving its NEO Surveyor Mission Into the Development Phase

Lead Image:
Illustration of the asteroid Bennu.
Credit: NASA Jet Propulsion Laboratory

The post Could We Use An Asteroid to Shield Astronauts On Their Way to Mars? appeared first on Universe Today.

Today’s Jesus and Mo strip, called “cursed,: came with the note, “It’s Tahir Ali MP.” The link goes to Mr. Ali calling for blasphemy laws protecting all religious texts, including of course the Qur’an.

Jesus’s logic gets Mo all balled up, and in the end Mo gets to the real point of Ali’s proposal

Large-scale production of organic solar cells with high efficiency and minimal environmental impact. In the study, the researchers studied molecule shape and interaction in organic solar cells.

Two massive asteroids hit Earth around 35.65 million years ago, but did not lead to any lasting changes in the Earth's climate, according to a new study.

Scientists carried out an experiment that realizes a new kind of quantum standard of resistance. It's based on the Quantum Anomalous Hall Effect.

Scientists carried out an experiment that realizes a new kind of quantum standard of resistance. It's based on the Quantum Anomalous Hall Effect.