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Ophiocoma Wendtii Is The Second Known Creature That Can See Without Eyes – Dual Dove

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Ophiocoma wendtii, a cousin of the starfish, doesn’t have eyes; however, the creature can see. The starfish inhabits the coral reefs of the Caribbean and Gulf of Mexico. Experts have studied the brittle red star, discovering that it is the second creature having extraocular vision joining a single species of sea urchin.

The Ophiocoma wendtii can see without eyes due to its light-sensing cells (photoreceptors), coating its body and pigment cells (chromatophores), that shift during the day and provokes the creature’s color to switch from stripy beige at nighttime to deep reddish-brown in the daytime.

The brittle red star has long, thin arms emanating from a small, disk-shaped body and are about the size of an outstretched human hand. The sea animal lives in bright and complex habitats. It hides from reef fish predators during the daytime and feeds on detritus during nighttime.

The animal’s chromatophores surround its photoreceptors during the daytime. The process helps to narrow the field of the light being detected. Photoreceptors are similar to pixels that form an image when put together. However, this process is not visible during nighttime, when the chromatophores contract.

Ophiocoma Wendtii Is The Second Known Creature That Can See Without Eyes

“If our conclusions about the chromatophores are correct, this is a beautiful example of innovation in evolution,” said Lauren Sumner-Rooney, a research fellow at Oxford University Museum of Natural History who led the study.

Researchers have experimented with these brittle stars and discovered that they have an original vision. From the experiment, the brittle star moved its position toward walls that were white with a black bar, in a circular arena, showing its instinct to hide during the daytime.

Another experiment showed they were not merely detecting brightness versus darkness. The starfish were put in an arena with gray walls; they still drifted toward the black stripe, which was centered on a white line to display the same mass of light as the gray.

“It’s such an alien concept for us, as very visually driven animals, to conceive of how an animal might see its habitat without eyes, but now we know of two examples,” Sumner-Rooney added.


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Blood moon, big city: Skywatcher captures total lunar eclipse over New York – Galaxy Reporters

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Image Credit: FtLaud/Shutterstock

The moon during eclipse burns red high above the yellow lights of New York City in beautiful photos caught by novice astronomer Alexander Krivenyshev.

Alexander Krivenyshev is the president of WorldTimeZone.com, who snapped images of the total lunar eclipse on Sunday night (May 15) from Guttenberg, New Jersey, outside the Hudson River from the Big Apple.

Krivenyshev told Space.com through the email that he maintained through cloudy conditions to get shots of the blood-red moon glowing like a beacon in a light-polluted sky.

The eclipse started at 9:32 p.m EDT on Sunday (0132 GMT on May 16) when the moon nosed into the dark part of Earth’s shadow, recognized as the penumbra, and stopped five hours later. The total eclipse phase, in which Earth’s huger umbral shadow blackened the moon, survived 85 minutes longer than any lunar eclipse in 33 years.

Earth’s closest neighbor temporarily turns coppery red during entire lunar eclipses. This “blood moon” impact is caused by Earth’s atmosphere, which bends some red light throughout the lunar surface while scattering away shorter-wavelength light.

Last weekend’s sky show was nicely observed from America and fractions of Western Europe and West Africa. It was the first total lunar eclipse of the year; however, it won’t be the last. One more eclipse will occur on Nov. 8. The Nov. 8 lunar eclipse will be observed from Australia, eastern Asia, and the western United States.

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Searching for the Milky Way's Black Hole – Skywatching – Castanet.net

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When we look into the southern sky close to the horizon on summer evenings, we are looking towards the centre of our galaxy, the Milky Way.

It is lurking around 30,000 light years behind the stars making up the constellation of Sagittarius, “The Archer”. However, thanks to our location in the disc of our galaxy, our view is blocked by huge clouds of stars, gas and dust.

Our first images of the centre of the Milky Way were obtained by means of radio telescopes, which show us what the universe would look like if we could see radio waves rather than light. They revealed a strange, bright and unusually small radio source.

Measurements of the speeds stars orbit the centre of our galaxy indicate that at the same position as the bright radio source lies something very massive, very small and active. The best candidate to explain this is a black hole.

Radio waves have power to penetrate clouds and dust, which is why radar is so useful for navigation, detecting threats and avoiding hazards at night or in bad weather. However, radio waves have this greater penetration power because they are much longer than light waves. This means that to see detail when observing at radio wavelengths we need to use huge antennas.

To have the same ability to discern detail as the human eye, a radio telescope tuned to the wavelength of emissions from cosmic hydrogen (21cm) the antenna would need to be about a kilometre in diameter. Moreover, black holes are small by cosmic standards and at great distances, so to discern any details the radio telescope would need an antenna the size of the Earth.

This sounds impossible, but there is a solution, a technique called “Very Long Baseline Interferometry”.

In the 1960s, Canada was the first country to succeed in combining radio telescopes thousands of kilometres apart so that they would have the detail discerning ability of a radio telescope thousands of kilometres in diameter.

This procedure has made possible a powerful, new astronomical instrument, the Event Horizon Telescope (EHT).

Several radio telescopes, thousands of kilometres apart operate in collaboration to observe the centre of the Milky Way at the same time. One of them is the Atacama Large Millimetre Array, located in Chile, in which Canada is a partner. In addition, scientists at several Canadian universities are involved.

The collaboration is named after the boundary that forms around black holes, called the event horizon. This is a one-way boundary in space-time—stuff can fall in but nothing, not even light, gets out. This is why they are called black holes.

However, even if we cannot see the black holes directly, we can certainly see the disc of material swirling around the black holes as it gets sucked in. This stuff gets very hot, and has intense magnetic fields trapped in it, so the black hole announces itself with radio emissions and X-rays from that disc.

The first target for the Event Horizon Telescope was the galaxy M87, located some 55 million light years away. It had long been suspected that a very energetic black hole lies at its centre, a big one, around 5 billion times the mass of the Sun. The EHT gave us our first image of that black hole.

Then the EHT radio telescopes were turned on the centre of our galaxy, and got our first image of our black hole. Luckily for us, it is much less massive and active than the one at the centre of M87. At four million times the mass of the Sun, it is relatively tiny.

We believe most spiral galaxies have big black holes in their cores. It is not clear whether galaxies get them when they form or they appear later. However, learning about their roles in galaxies should tell us more about how galaxies form and evolve to the point where they develop stars and planets, and because we live in one, it would be nice to know.

•••

• Venus, Jupiter, Mars and Saturn are still lined up in the dawn glow, in order of decreasing brightness.

• The Moon will be new on May 30.

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.

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Boeing's Starliner approaching ISS in high-stakes test mission – Phys.org

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The Orbital Test Flight 2 (OFT-2) mission blasted off at 6:54 pm Eastern Time (2254 GMT) from the Kennedy Space Center in Florida, with the spaceship fixed atop a United Launch Alliance Atlas V rocket.

Boeing’s Starliner capsule was preparing to dock with the International Space Station Friday, in a high-stakes uncrewed test flight key to reviving the US aerospace giant’s reputation after a series of failures.

The spaceship blasted off from the Kennedy Space Center in Florida on Thursday evening, and is now set to rendezvous with the ISS at 7:10 pm Eastern Time (2310 GMT), as part of a mission to prove it is capable of providing safe rides for NASA astronauts.

Starliner encountered some propulsion problems early in its journey, with two thrusters responsible for placing it in a stable orbit failing for unclear reasons—though officials insisted everything remained on track.

“Overall, the spacecraft is doing really well,” Steve Sitch, program manager for NASA’s Commercial Crew Program told reporters at a post-launch press conference, in which he nonetheless flagged anomalies that engineers are working to understand.

One of 12 orbital maneuvering and (OMAC) thrusters located on Starliner’s aft side failed after one second, at which point a second thruster kicked in and took over, but also cut out after 25 seconds.

The ship’s software then engaged a third thruster that completed the necessary burn.

The OMAC thrusters are set to be used to bring Starliner closer to the ISS, and to help de-orbit the spacecraft near the end of the mission.

NASA is looking to certify Starliner as a second "taxi" service for its astronauts to the space station -- a role that
NASA is looking to certify Starliner as a second “taxi” service for its astronauts to the space station — a role that Elon Musk’s SpaceX has provided since succeeding in a test mission for its Dragon capsule in 2020.

“We’ll go look at the data and try to understand what happened. And then from a redundancy perspective, can we recover those thrusters?” said Sitch.

Starliner’s success is key to repairing Boeing’s frayed reputation after its first launch, back in 2019, failed to dock with the ISS due to software bugs—one that led to it burning too much fuel to reach its destination, and another that could have destroyed the vehicle during re-entry.

A second try was scheduled in August 2021, but the capsule was rolled back from the launchpad to address sticky valves that weren’t opening as they should, and the vessel was eventually sent back to the factory for fixes.

NASA is looking to certify Starliner as a second “taxi” service for its astronauts to the —a role that Elon Musk’s SpaceX has provided since succeeding in a test mission for its Dragon capsule in 2020.

Seeking redemption

Both companies were awarded fixed-price contracts—$4.2 billion to Boeing, and $2.6 billion to SpaceX—in 2014, shortly after the end of the Space Shuttle program, during a time when the United States was left reliant on Russian Soyuz rockets for rides to the orbital outpost.

Boeing, with its hundred-year history, was considered by many as the sure shot, while then-upstart SpaceX was less proven.

Starliner should dock with the ISS about 24 hours after launch, and deliver more than 500 pounds (226 kilograms) of cargo -- inc
Starliner should dock with the ISS about 24 hours after launch, and deliver more than 500 pounds (226 kilograms) of cargo — including food and provisions like clothes and sleeping bags for the current crew on the station.

In reality, it was SpaceX that rocketed ahead, and recently sent its fourth routine crew to the research platform—while Boeing’s development delays have cost the company hundreds of millions of dollars.

Starliner should dock with the ISS about 24 hours after launch, and deliver more than 800 pounds of cargo.

Its sole passenger is a mannequin named Rosie the Rocketeer—a play on the World War II campaign icon Rosie the Riveter—whose job is to collect flight data with her sensors in order to learn what human astronauts would experience.

“We are a little jealous of Rosie,” NASA astronaut Mike Fincke, who is expected to be among the first crew selected for a manned demonstration mission should OFT-2 succeed, said at a press conference this week.

The gumdrop-shaped capsule will spend about five days in space, then undock and return to Earth on May 25, using giant parachutes to land in the desert of the western United States.

NASA sees a second provider to low Earth orbit as a vital backup, should SpaceX encounter problems.


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Boeing’s Starliner encounters propulsion problems on way to ISS


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Boeing’s Starliner approaching ISS in high-stakes test mission (2022, May 20)
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