Tag: Space

Radio Search for Artificial Emissions from ‘Oumuamua

It’s the first time a visitor from another star system has been seen nearby. But what is it? An asteroid, a comet … or an alien artifact?

Scientists at the SETI Institute have attempted to address this question by using the Allen Telescope Array (ATA) to observe ‘Oumuamua when it was about 170 million miles away, or slightly less than the diameter of Earth’s orbit.

The intention was to measure artificial radio transmissions which, if found, would be strong evidence that this object is not simply a rock tossed into space by a random gravitational slingshot interaction that occurred in its home star system.

“We were looking for a signal that would prove that this object incorporates some technology – that it was of artificial origin,” says Gerry Harp, lead author of a paper to be published in the February 2019 issue of Acta Astronautica.

“We didn’t find any such emissions, despite a quite sensitive search. While our observations don’t conclusively rule out a non-natural origin for ‘Oumuamua, they constitute important data in accessing its likely makeup.”

Following its discovery in October 2017, ‘Oumuamua was the subject of popular speculation about a possible non-natural origin largely because it brought to mind the interstellar spaceship in Arthur C. Clarke’s novel Rendezvous with Rama. Its highly elongated shape and the fact that no coma was observed strengthened this hypothesis for some, as these are uncharacteristic of asteroids and comets.

A recent paper published in Astrophysical Journal Letters by researchers at Harvard has also suggested the possibility that ‘Oumuamua is a deliberate construction. The Harvard researchers argue that the slight, unexpected acceleration observed for this object could be caused by pressure from sunlight as ‘Oumuamua swung around the Sun.

Their hypothesis is that the object might be a light sail, either deliberately or accidentally sent our way. A deliberate origin is considered somewhat more likely because our solar system is a very small target for any object that is not being aimed.

Such arguments strengthen the importance of observations such as those conducted on the ATA that can constrain the true nature of ‘Oumuamua.

Observations were made between November 23 and December 5, 2017, using the wide-band correlator of the ATA at frequencies between 1 and 10 GHz and with a frequency resolution of 100 kHz. No signals were found at a level that would be produced by an omnidirectional transmitter on-board the object of power 30 to 300 milliwatts.

In portions of the radio spectrum that are routinely cluttered by artificial satellite telemetry, the threshold for detection was as high as 10 watts. In all cases, these limits to the powers that could be detected are quite modest – comparable to that of cell phones or citizen band radios.

While no signals were found coming from ‘Oumuamua, the types of observations reported by SETI Institute scientists may have utility in constraining the nature of any interstellar objects detected in the future, or even the small, well-known objects in our own solar system.

It has been long-hypothesized that some of the latter could be interstellar probes, and radio observations offer a way to address this imaginative, but by no means impossible, idea.

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Russia Implies Americans Sabotaged International Space Station

Russian investigators looking into the origin of a hole that caused an oxygen leak on the International Space Station have said it was caused deliberately, the space agency chief said.

A first commission had delivered its report, Dmitry Rogozin, the head of the Russian space agency Roskosmos, said in televised remarks late Monday.

“It concluded that a manufacturing defect had been ruled out which is important to establish the truth.”

Rogozin said the commission’s main line of inquiry was that the hole had been drilled deliberately, a position that has been voiced in the past.

“Where it was made will be established by a second commission, which is at work now,” he said.

The small hole in the wall of a Russian-made Soyuz space capsule docked onto the ISS was located in August and quickly sealed up.

Officials have suggested a number of possible reasons for the appearance of the hole.

A top government official has denied a Russian media report that the investigation looked at the possibility that US astronauts had drilled the hole in order to get a sick colleague sent back to Earth.

The current ISS commander, US astronaut Drew Feustel, called the suggestion that the crew was somehow involved “embarrassing”.

Rogozin — who previously oversaw the Russian space industry as deputy prime minister — was appointed head of Roskosmos last May, in a move analysts said would spell trouble for the embattled sector.

The official, who was placed under US sanctions over the Ukraine crisis in 2014, admitted it had become difficult to work with NASA.

“Problems with NASA have certainly appeared but not through the fault of NASA,” he said, blaming unnamed American officials for telling the US space agency what to do.

He also claimed that SpaceX founder Elon Musk sought to squeeze Russia out of the space launch services market and complained about the US military drone X-37.

“Americans have this thing, the X-37,” Rogozin said. “We don’t understand its purposes. Rather, we do understand, but we have not received an official explanation.

“Essentially, this thing can be used as a weapons carrier.”

What this has to do with the investigation into a hole in the ISS is unknown, and the question remains: Could anyone take a drill to the ISS, a small contained environment with less internal area than many houses, with external cameras, and go unnoticed?

NASA representatives assure us that space walks are all carefully monitored in real time to assure astronaut safety.

The Sentinel believes that if the hole was drilled deliberately, the mostly likely explanation is that it must have been done before the capsule left  Earth. That means Russia.

Defending The Earth, A New U.S. Space Force?

U.S. President Donald Trump’s desire to create a Space Force might sound a little out of this world, but the idea of making military use of space is not new.

“We already, in fact, have a kind of Space Force,” says Ilya Somin, a professor of law at George Mason University. “We have military satellites that already exist. They’ve existed for a long time. It’s just that they’re controlled by the Air Force and sometimes by the Navy. So if Trump succeeds in persuading Congress to create a Space Force, all that will happen, at least initially, is that the sort of thing that was previously done by the Air Force will now be done by the Space Force.”

The U.S. military is currently composed of five armed services – the Army, Navy, Air Force, Marine Corps and Coast Guard. President Trump wants the Space Force to become a sixth military service branch focused on space warfare.

Constitutional scholars are debating how such a force would come into existence. Some question whether the U.S. Constitution, the nation’s founding governing document, allows for the establishment of a Space Force.

The Constitution grants Congress the power to “raise and support Armies” and also to “provide and maintain a Navy.”

Originalists, scholars who believe the Constitution should be interpreted as it was understood at the time it was enacted back in 1787, might argue that even the Air Force, which became a separate branch of the U.S. Armed Forces in 1947, should be considered unconstitutional.

Yet originalists could defend a Space Force if it were to be part of the Navy or Army, as the Air Force once was.

“A Space Force, like an Air Force, under modern conditions, is essential to conducting ground operations. It’s just another weapon for ground operations and sometimes naval operations,” Somin says. “The Constitution nowhere limits the kinds of weapons the Army or Navy is allowed to have. So if they’re allowed to have bullets that fly through the air, they can have planes that fly through the air and even spacecraft that fly through space.”

Originalists could also make a case for a completely separate Space Force organizationally because the Constitution gives Congress powers to do what is “necessary and proper” to enable lawmakers to execute their powers.

Agreeing that a Space Force is constitutional might come easily to “living constitutionalists,” scholars who believe that the meaning of the Constitution can change over time to account for modern conditions.

There is, however, one kind of Space Force that both originalists and living constitutionalists might have a problem with – a deep Space Force along the lines of Star Trek’s science fictional Starfleet, which conducts interstellar warfare, exploration and colonization.

“If you’re talking about the Starship Enterprise and it’s light years away from Earth and it’s fighting the Klingons or something in space, that has little or no connection to ground or naval warfare,” says Somin, adding, “I think there is a genuinely strong argument that that kind of deep Space Force would not be permissible under the original meaning of the Constitution.”

But what if aliens in a galaxy far, far away, plan to attack Earth?

“Any such thing, [our ability to use technology for deep space interstellar flight], if it ever happens at all, is many decades away probably, so we have plenty of time to discuss it and debate it, and if we decide this is something we really need, we can do a constitutional amendment,” Somin says. “It’s not like the Klingons or the Romulans are about to attack us tomorrow and we have to immediately authorize Starfleet to defeat them.”

Failed Star Presents Unique Opportunities

A rogue, planet-size object 20 light-years away from Earth has stunned astronomers with its incredibly powerful magnetic field.

The scientists found that the object’s magnetic field is more than 200 times stronger than Jupiter’s, which, in turn, is between 16 and 54 times stronger than Earth’s, according to NASA. How the object, which scientists call SIMP J01365663+0933473, can maintain a magnetic field so strong, as well as generate spectacular auroras, is still unclear.

“This particular object is exciting because studying its magnetic dynamo mechanisms can give us new insights on how the same type of mechanisms can operate in extrasolar planets — planets beyond our solar system,” lead study author Melodie Kao, an astrophysicist at Arizona State University, said in a statement from the National Radio Astronomy Observatory published Aug. 2.

It’s not just the magnetic mechanism that’s leaving scientists with questions right now — there are plenty of other mysteries about the object, which scientists first discovered in 2016.

The object is what scientists call a brown dwarf. Nicknamed “failed stars,” brown dwarfs are larger than planets, but not quite large enough to fuse hydrogen, the way stars do. The boundary line is still debated, but scientists tend to draw it at about 13 times the mass of Jupiter.

Originally, scientists thought SIMP J01365663+0933473 was a gigantic, old brown dwarf. But further study showed that it is instead relatively young, at 200 million years old, and is only 12.7 times the mass of Jupiter. That research also showed that the planet is on its own, not orbiting a star.

“This object is right at the boundary between a planet and a brown dwarf, or ‘failed star,’ and is giving us some surprises that can potentially help us understand magnetic processes on both stars and planets,” Kao said in the statement. “We think these mechanisms can work not only in brown dwarfs, but also in both gas giant and terrestrial planets.”
The team is particularly excited by the new research because it relies in part on radio observations of the object’s auroras — which means that radio telescopes may be able to identify new planets by their auroras.

The new research was described in an article published July 31 in the Astrophysical Journal.
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NASA: Six Facts About Recovering The Mars Opportunity Rover

NASA’s Opportunity rover has been silent since June 10, when a planet-encircling dust storm cut off solar power for the nearly-15-year-old rover. Now that scientists think the global dust storm is “decaying” — meaning more dust is falling out of the atmosphere than is being raised back into it — skies might soon clear enough for the solar-powered rover to recharge and attempt to “phone home.”

No one will know how the rover is doing until it speaks. But the team notes there’s reason to be optimistic: They’ve performed several studies on the state of its batteries before the storm, and temperatures at its location. Because the batteries were in relatively good health before the storm, there’s not likely to be too much degradation. And because dust storms tend to warm the environment — and the 2018 storm happened as Opportunity’s location on Mars entered summer — the rover should have stayed warm enough to survive.

What will engineers at NASA’s Jet Propulsion Laboratory in Pasadena, California, be looking for — and what will those signs mean for recovery efforts?

A tau below 2

Dust storms on Mars block sunlight from reaching the surface, raising the level of a measurement called “tau.” The higher the tau, the less sunlight is available; the last tau measured by Opportunity was 10.8 on June 10. To compare, an average tau for its location on Mars is usually 0.5.

JPL engineers predict that Opportunity will need a tau of less than 2.0 before the solar-powered rover will be able to recharge its batteries. A wide-angle camera on NASA’s Mars Reconnaissance Orbiter will watch for surface features to become visible as the skies clear. That will help scientists estimate the tau.

Updates on the dust storm and tau can be found here.

Two Ways to Listen for Opportunity

Several times a week, engineers use NASA’s Deep Space Network, which communicates between planetary probes and Earth, to attempt to talk with Opportunity. The massive DSN antennas ping the rover during scheduled “wake-up” times, and then search for signals sent from Opportunity in response.

In addition, JPL’s radio science group uses special equipment on DSN antennas that can detect a wider range of frequencies. Each day, they record any radio signal from Mars over most of the rover’s daylight hours, then search the recordings for Opportunity’s “voice.”

Rover faults out

When Opportunity experiences a problem, it can go into so-called “fault modes” where it automatically takes action to maintain its health. Engineers are preparing for three key fault modes if they do hear back from Opportunity.

  • Low-power fault: engineers assume the rover went into low-power fault shortly after it stopped communicating on June 10. This mode causes the rover to hibernate, assuming that it will wake up at a time when there’s more sunlight to let it recharge.
  • Clock fault: critical to operating while in hibernation is the rover’s onboard clock. If the rover doesn’t know what time it is, it doesn’t know when it should be attempting to communicate. The rover can use environmental clues, like an increase in sunlight, to make assumptions about the time.
  • Uploss fault: when the rover hasn’t heard from Earth in a long time, it can go into “uploss” fault — a warning that its communication equipment may not be functioning. When it experiences this, it begins to check the equipment and tries different ways to communicate with Earth.

What happens if they hear back?

After the first time engineers hear from Opportunity, there could be a lag of several weeks before a second time. It’s like a patient coming out of a coma: It takes time to fully recover. It may take several communication sessions before engineers have enough information to take action.

The first thing to do is learn more about the state of the rover. Opportunity’s team will ask for a history of the rover’s battery and solar cells and take its temperature. If the clock lost track of time, it will be reset. The rover would take pictures of itself to see whether dust might be caked on sensitive parts, and test actuators to see if dust slipped inside, affecting its joints.

Once they’ve gathered all this data, the team would take a poll about whether they’re ready to attempt a full recovery.

Not out of the woods

Even if engineers hear back from Opportunity, there’s a real possibility the rover won’t be the same.

The rover’s batteries could have discharged so much power — and stayed inactive so long — that their capacity is reduced. If those batteries can’t hold as much charge, it could affect the rover’s continued operations. It could also mean that energy-draining behavior, like running its heaters during winter, could cause the batteries to brown out.

Dust isn’t usually as much of a problem. Previous storms plastered dust on the camera lenses, but most of that was shed off over time. Any remaining dust can be calibrated out.

Send Opportunity a postcard

Do you miss Opportunity as much as the rover’s team? You can write a message sharing your thoughts here.

Read more about Opportunity at:

https://mars.nasa.gov/mer/highlights/