Jupiter

Harvard prof doesn’t back down from claims that alien spacecraft may be zipping past Jupiter orbit

A distinguished Harvard University professor is not backing down from his claims that a piece of extraterrestrial spacecraft technology may be flying past the orbit of Jupiter at this moment. Avi Loeb, one of the top astronomy professors in the world, boasting of decades of Ivy League professorships and hundreds of publicized works in respected astronomy publications, is remaining defiant that the space object – dubbed as “Oumuamua” – first noticed by Hawaiian astronomers in 2017 could be from another civilization. “Considering an artificial origin, one possibility is that ‘Oumuamua is a lightsail, floating in interstellar space as a debris from an advanced technological equipment,” Loeb and his colleague Shmuel Bialy wrote in Astrophysical Journal Letters in November, according to the Washington Post. Since making the shock claim last year, many scientists have criticized Loeb for offering, in their view, the most sensationalist theory of what the object is. “Oumuamua is not an alien spaceship, and the authors of the paper insult honest scientific inquiry to even suggest it,” Ohio State University astrophysicist Paul M. Sutter wrote in a tweet. Other scientists are more diplomatic and haven’t publicly countered Loeb’s claims, only saying that the object is likely just some sort of rock, whether it’s a piece of an asteroid or a comet. But Loeb remains stubborn on this theory, and dismisses the claims that it’s a rock, noting that it’s moving too fast for an inert rock. He told the Post that the object is long yet no more than one millimeter thick, and that it’s so light that sunlight is moving the object out of the solar system. “Many people expected once there would be this publicity, I would back down,” Loeb says. “If someone shows me evidence to the contrary, I will immediately back down.” “It changes your perception on reality, just knowing that we’re not alone,” he continued.

Things that make you go, “hmmmm”   For more, click on the text above.      🙂

NASA’s Juno spacecraft enters Jupiter’s orbit

Braving intense radiation, a NASA spacecraft reached Jupiter on Monday after a five-year voyage to begin exploring the king of the planets. Ground controllers at the NASA Jet Propulsion Laboratory erupted in applause when the solar-powered Juno spacecraft beamed home news that it was circling Jupiter’s poles. The arrival at Jupiter was dramatic. As Juno approached its target, it fired its rocket engine to slow itself down and gently slipped into orbit. Because of the communication time lag between Jupiter and Earth, Juno was on autopilot when it executed the daring move. The spacecraft’s camera and other instruments were switched off for arrival, so there won’t be any pictures at the moment it reaches its destination. Hours before the encounter, NASA released a series of images taken last week during the approach, showing Jupiter glowing yellow in the distance, circled by its four inner moons. Scientists have promised close-up views of the planet when Juno skims the cloud tops during the 20-month, $1.1 billion mission. The fifth rock from the sun and the heftiest planet in the solar system, Jupiter is what’s known as a gas giant — a ball of hydrogen and helium — unlike rocky Earth and Mars. With its billowy clouds and colorful stripes, Jupiter is an extreme world that likely formed first, shortly after the sun. Unlocking its history may hold clues to understanding how Earth and the rest of the solar system developed. Named after Jupiter’s cloud-piercing wife in Roman mythology, Juno is only the second mission designed to spend time at Jupiter. Galileo, launched in 1989, circled Jupiter for nearly a decade, beaming back splendid views of the planet and its numerous moons. It uncovered signs of an ocean beneath the icy surface of the moon Europa, considered a top target in the search for life outside Earth. Juno’s mission: To peer through Jupiter’s cloud-socked atmosphere and map the interior from a unique vantage point above the poles. Among the lingering questions: How much water exists? Is there a solid core? Why are Jupiter’s southern and northern lights the brightest in the solar system? “What Juno’s about is looking beneath that surface,” Juno chief scientist Scott Bolton said before the arrival. “We’ve got to go down and look at what’s inside, see how it’s built, how deep these features go, learn about its real secrets.” There’s also the mystery of its Great Red Spot. Recent observations by the Hubble Space Telescope revealed the centuries-old monster storm in Jupiter’s atmosphere is shrinking. The trek to Jupiter, spanning nearly five years and 1.8 billion miles (2.8 billion kilometers), took Juno on a tour of the inner solar system followed by a swing past Earth that catapulted it beyond the asteroid belt between Mars and Jupiter. Along the way, Juno became the first spacecraft to cruise that far out powered by the sun, beating Europe’s comet-chasing Rosetta spacecraft. A trio of massive solar wings sticks out from Juno like blades from a windmill, generating 500 watts of power to run its nine instruments. In the coming days, Juno will turn its instruments back on, but the real work won’t begin until late August when the spacecraft swings in closer. Plans called for Juno to swoop within 3,000 miles (5,000 kilometers) of Jupiter’s clouds — closer than previous missions — to map the planet’s gravity and magnetic fields in order to learn about the interior makeup. Juno, built by Lockheed Martin, is an armored spacecraft — its computer and electronics are locked in a titanium vault to shield them from harmful radiation. Even so, Juno is expected to get blasted with radiation equal to more than 100 million dental X-rays during the mission. Like Galileo before it, Juno meets its demise in 2018 when it deliberately dives into Jupiter’s atmosphere and disintegrates — a necessary sacrifice to prevent any chance of accidentally crashing into the planet’s potentially habitable moons.

Very cool!   🙂

Jupiter moon Europa’s ocean may have enough energy to support life

Jupiter’s moon Europa might be able to support life even if there’s little or no volcanic activity under the satellite’s icy shell, a new study suggests. A salty ocean of liquid water is believed to lie beneath Europa’s icy exterior. Scientists think this ocean could be habitable, if it harbors the required chemical building blocks and the right proportion of elements to provide energy for biological systems — the right ratio of oxygen to hydrogen, for example. The new study suggests that there is, indeed, enough of that energy. A research team led by Steve Vance, of NASA’s Jet Propulsion Laboratory in Pasadena, California, found that, even without taking possible volcanic processes into account, Europa likely produces 10 times more oxygen than hydrogen, just as Earth does. According to the team’s calculations, Europa’s hydrogen is generated as seawater reacts with rock in the moon’s crust. Europa has cooled slowly over the eons, forming new cracks in the crust that expose more rock to seawater, thus generating more hydrogen, the researchers said. Meanwhile, the oxygen would come from ice on Europa’s surface. Radiation from Jupiter — which is far more intense than anything experienced on Earth’s surface — breaks water molecules into hydrogen and oxygen. The oxygen then reacts with other compounds in the water as well as the hydrogen. As the oxidants sink, they get recycled into Europa’s interior, and then into the ocean, study team members said. Until now, many planetary scientists thought that Europa, kneaded by Jupiter’s gravity, would be volcanically active. After all, the neighboring moon Io is the most volcanically active body in the solar system; Jupiter’s gravity and tidal forces deform Io’s crust and mantle, generating huge amounts of heat. Something similar could be happening at Europa, but nobody knows for sure if it is. Much speculation about possible Europan life envisions a biosphere that resembles the clusters of life found near hydrothermal vents on Earth’s ocean floor. But the new research suggests that volcanism isn’t necessary to cycle chemicals through the ocean, and thus is probably not necessary for living things to survive, study team members said. The study was published online in the journal Geophysical Research Letters.

Fascinating!!   🙂

NASA Jupiter probe sets distance record for solar-powered spacecraft

A NASA spacecraft in the home stretch of its five-year journey to Jupiter has just become the farthest-flung solar-powered probe in history. On Wednesday, NASA’s Juno spacecraft zoomed past the previous record of 492 million miles from the sun, which was held by the European Space Agency’s comet-chasing Rosetta mission, NASA officials said. Juno is scheduled to enter orbit around Jupiter on July 4, and shortly thereafter begin mapping out the gas giant’s powerful gravitational and magnetic fields in precise detail. These observations should reveal a great deal about the planet’s structure, formation and evolution, including whether or not it has a solid core, mission team members have said. “Juno is all about pushing the edge of technology to help us learn about our origins,” Juno principal investigator Scott Bolton, of the Southwest Research Institute in San Antonio, said in a statement. “We use every known technique to see through Jupiter’s clouds and reveal the secrets Jupiter holds of our solar system’s early history,” Bolton added. “It just seems right that the sun is helping us learn about the origin of Jupiter and the other planets that orbit it.” The 4-ton Juno probe carries three 30-foot-long (9 meters) solar panels, which hold a total of 18,698 individual solar cells, enough to generate 14 kilowatts of electricity here on Earth, NASA officials said. But the situation will be quite different at Jupiter. “Jupiter is five times farther from the sun than Earth [is], and the sunlight that reaches that far out packs 25 times less punch,” Juno project manager Rick Nybakken, of NASA’s Jet Propulsion Laboratory in Pasadena, California, said in the same statement. “While our massive solar arrays will be generating only 500 watts when we are at Jupiter, Juno is very efficiently designed, and it will be more than enough to get the job done.” The other eight space missions that have traveled as far as Jupiter have relied on nuclear energy to power their instruments. Juno is making history by leveraging advanced solar-cell technology and an energy-efficient spacecraft and science gear. The probe’s mission and orbit design will also help, allowing Juno to avoid Jupiter’s shadow and minimizing the spacecraft’s exposure to the giant planet’s harsh radiation environment, NASA officials said. The $1.1 billion Juno mission, which launched on Aug. 5, 2011, will continue adding to the distance record for a while yet. The probe will eventually get a maximum of 517 million miles (832 million km) from the sun during its 16-month science mission, NASA officials said. “It is cool we got the record and that our dedicated team of engineers and scientists can chalk up another first in space exploration,” Bolton said. “But the best is yet to come. We are achieving these records and venturing so far out for a reason — to better understand the biggest world in our solar system and thereby better understand where we came from.” Europe’s Rosetta mission set the previous distance record in October 2012, while it was chasing down Comet 67P/Churyumov-Gerasimenko. Rosetta caught the comet in August 2014, and in November of that year, the probe dropped a lander called Philae onto the icy object’s surface. Rosetta is still orbiting Comet 67P, which made its closest approach to the sun in August 2015 and is now zooming back toward the outer solar system. The comet and Rosetta are currently about 196.4 million miles from the sun, according to the European Space Agency’s Rosetta-tracking website. Rosetta will not get a chance to break Juno’s record. The European probe will end its mission by spiraling down onto Comet 67P’s surface on Sept. 30 of this year, when the pair are about 356 million miles from the sun.

Very cool!!   🙂

Space bully: Jupiter may have kicked giant planet out of its orbit

It seems that some planets just can’t play nicely together. Scientists at the University of Toronto have discovered that Jupiter may have ejected another planet from the Solar System 4 billion years ago. The astrophysicists detailed their findings in a new study published in The Astrophysical Journal, noting the existence of a fifth gas planet when the Solar System formed, a theory that was first proposed in 2011. Jupiter, Saturn, Uranus and Neptune are the other gas planets. Planet ejections occur following a close planetary encounter in which one of the objects accelerates so much that it breaks free from the massive gravitational pull of the Sun, according to the University of Toronto. Either Jupiter or Saturn was suspected to be the culprit. “Our evidence points to Jupiter,” said Ryan Cloutier, a doctoral candidate in the University’s department of astronomy and astrophysics, and the study’s lead author, in a statement. Experts, however, had not previously considered the impact of a planet ejection on other orbiting bodies, such as moons. The University of Toronto scientists used computer simulations based on the current trajectories of Callisto and Iapetus, moons of Saturn and Jupiter, respectively. They also examined the possibility that the moons could maintain their orbit in the event that their host planet ejected another planet from the solar system. “Ultimately, we found that Jupiter is capable of ejecting the fifth giant planet while retaining a moon with the orbit of Callisto,” said Cloutier, in the statement. “On the other hand, it would have been very difficult for Saturn to do so because Iapetus would have been excessively unsettled, resulting in an orbit that is difficult to reconcile with its current trajectory.”

Fascinating!!   🙂

Water, water everywhere in our solar system’s moons

The confirmation of a subterranean ocean underneath the icy surface of Jupiter’s moon Ganymede is the latest thread in a mounting body of evidence that water – and by theoretical extension, life – in our solar system need not be relegated solely to the narrow neither too hot nor too cold orbit known as the Goldilocks zone inhabited by Earth. With this confirmation, announced Thursday by NASA, Ganymede joins the ranks of two other moons that lie beyond the reach of the sun’s warmth and are believed to host underground reservoirs of liquid water. Evidence of similar oceans has been detected on Europa, another of Jupiter’s moons, and Enceledus, which orbits Saturn. This growing body of evidence that one of the key ingredients for life exists outside the range that was once considered to be the solar system’s only hospitable zone has prompted astronomers to completely rethink where and how they look for signs of life elsewhere in the solar system. “One of the things that we have learned in the last few decades is that life as we know it is not as we knew it,” says Nick Schneider, professor at the University of Colorado’s Department of Astrophysical and Planetary Science in Boulder, Colo. While the quest for evidence of microbial life in the solar system may seem inconsequential to Earthlings, discovery of any form of life, however small, could hold profound clues about the origin of life on our own planet, says Dr. Schneider, who was not involved in the Ganymede research, but serves as the instrument lead on the Imaging UltraViolet Spectrograph for NASA’s MAVEN mission to Mars. “I think that people will really come to accept this as the most profound question that we can ask,” he says. Astronomers first began to theorize that factors other than proximity to the sun could raise temperatures on other worlds to levels conducive to liquid water even before the first Voyager flybys around the Jupiter system in the 1980s, says planetary scientist Heidi Hammel, the executive vice president of the Association of Universities for Research in Astronomy (AURA) in Washington, D.C. “What we’re learning is that the sun and its warmth isn’t the only way to get warmth in the solar system and we’ve been thinking that for some time,” Dr. Hammel says. “However, there’s a difference between having a theory about something and having evidence that the model is correct.”

Indeed.  Very cool!    🙂