Month: January 2019

Probe fails to detect water on asteroid Ryugu

Asteroid belongs to category of objects known to contain moisture in surface boulders.

The Japanese Aerospace Exploration Agency’s (JAXA) Hayabusa2 spacecraft has not detected any evidence of water on the asteroid Ryugu.

Since arriving at the asteroid in June of this year, the probe has studied 54,000 spots on its surface. Among the data the spacecraft returned are close up images of surface boulders and ridges.

Ryugu is classed as a C-type asteroid, a category of asteroids that contain high levels of carbon and often have moisture in the boulders on their surfaces. Scientists would like to find evidence of such moisture on Ryugu, as the presence of water could make the asteroid habitable for microbial life.

Located 186.4 million miles (300 million km) from Earth, Ryugu, which rotates on its axis once every 7.5 hours and takes 474 days to orbit the Sun, is too small and distant for observers on Earth to see its surface details.

Mission scientists are not giving up on the possibility that evidence of water might still be found on Ryugu. The probe will continue studying the near-Earth asteroid for a year and a half, during which time it will drop four small rovers on Ryugu’s surface.

After identifying an ideal landing site, the spacecraft will touch down on the surface this fall, then create a hole in that surface for sample collection by firing a metal fragment into it.

Hayabusa2 is a sample return mission, meaning the probe will collect samples from the asteroid’s surface and subsurface and return them to Earth for analysis. It will leave Ryugu in December 2019 and arrive back on Earth with the samples a year later.

“There is a possibility that water  might be discovered after an artificial crater is created on its surface next spring,” said JAXA project member Kohei Kitazato, a professor of Earth and planetary science astronomy at the University of Aizu.

Even if no evidence of water is found on Ryugu, that does not mean it never had water. It is possible that surface water once was present but subsequently evaporated, possibly through interaction with light from the Sun.

 

 

More mini-moons may be found in the future, study reports

Astronomers believe that new technology could lead to the discovery of more mini-moons, a process that could shed more light on asteroid composition.

A of team of international astronomers believe new space technology could be used to track and monitor mini-moons, according to new research published in the journal Frontiers in Astronomy and Space Sciences.

Nearly 12 years ago scientists detected a tiny asteroid known as 2006 RH120. They took interest in the small space rock because it was the first-known natural object to orbit Earth other than the moon.

Though scientists predicted they would find more of those “mini-moons” — asteroids that measure just 39 to 79 inches across and get temporarily caught in the Earth’s orbit — in the future, they have had no such luck. The team in the recent study states that is because current technology is not quite there.

Mini-moons are extremely small and move incredibly fast. That combination makes it so current asteroid surveys are not able to detect them.

“Mini-moons can provide interesting science and technology testbeds in near-Earth space,” said lead author Robert Jedicke, a researcher at the University of Hawaii, in a Newsweek. “These asteroids are delivered towards Earth from the main asteroid belt between Mars and Jupiter via gravitational interactions with the Sun and planets in our solar system. The challenge lies in finding these small objects, despite their close proximity.”

The reason mini-moons are so important is because they could one day help scientists gain a better understanding of both asteroids and the Earth-moon system.

Currently, researchers do not fully know what asteroids are made of. Mini-moons could give them insight into that make-up and potentially allow better analysis of deep space rocks. New technology will make that happen.

For instance, the upcoming Large Synoptic Survey Telescope (LSST) — set to be operational in a few years — could use its large mirror and wide field camera to pick up mini-moons traveling through space.

“I hope that humans will someday venture into the solar system to explore the planets, asteroids and comets—and I see mini-moons as the first stepping stones on that voyage,” added Jedicke, according to Phys.org

The tiny bodies could be the perfect platform for companies to develop or test both asteroid mining and planetary defense technologies as well.

Scientists finally explain Jupiter’s colorful bands

A new study offers the first concrete explanation for why Jupiter is covered in bright, colorful bands.

Astronomers from the Lawrence Livermore National Laboratory and the Australian National University may have finally uncovered the mystery behind Jupiter’s brightly colored bands, a new study in the Astrophysical Journal reports.

Jupiter is unique because, unlike many planets, it has no solid surface. Rather, it is completely made up of gas.

As a part of that, its upper atmosphere has several strong jet streams that carry clouds of different elements across the planet. That process then creates colored bands that range from shades of red and orange to brown and yellow.

While scientists have long postulated on how Jupiter’s jets form and how they move beneath the clouds, they have never been able to observe the phenomena until now.

“We know a lot about the jet streams in Earth’s atmosphere and the key role they play in the weather and climate, but we still have a lot to learn about Jupiter’s atmosphere,” said lead author Navid Constantinou, a researcher from the Australian National University’s Research School of Earth Sciences, according to Newsweek. “Scientists have long debated how deep the jet streams reach beneath the surfaces of Jupiter and other gas giants, and why they do not appear in the Sun’s interior.”

To take a close look at that mystery, the team behind the research analyzed data collected by NASA’s Juno spacecraft. That then showed the jet streams dip down at least 1,800 miles below the clouds.

Using that data in combination with a mathematical model, the team predicts the jets can become suppressed if magnetic fields ever get strong enough. That would then explain why the streams can only penetrate so far.

This new finding is important because, not only does it provide insight into the planet, but it helps further research about gas giants in general.

“There are no continents and mountains below Jupiter’s atmosphere to obstruct the path of the jet streams,” said study co-author Jeffrey Parker, a researcher at the Livermore National Laboratory, according to Phys.org. “This makes the jet streams on Jupiter simpler. By studying Jupiter, not only do we unravel the mysteries in the interior of the gas giant, but we can also use Jupiter as a laboratory for studying how atmospheric flows work in general.”

New Horizons spots ‘hydrogen wall’ at edge of solar system

For the first time in history scientists believe they may be able to view the mysterious “hydrogen wall” that sits at the edge of our solar system.

For the first time in history astronomers believe they may be able to see the so-called “hydrogen wall” at the distant edge of our solar system, according to a new study in the journal Geophysical Research Letters.

The hydrogen wall is a boundary that sits at the edge of our home system. It is where the sun’s bubble of solar wind ends and where a mass of interstellar matter that is too small to break through that wind builds up. That then creates a visible boundary that has the last remains of solar wind on one side and interstellar matter on the other.

While scientists have never been able to view the odd phenomenon before, they believe that is about to change.

New Horizons, the craft that moved past Pluto in 2015, is able to see extra ultraviolet light out at the space where the wall should be. In addition, it also appears to be the same light that NASA’s probes first detected back in 1992.

While such observations are promising, they do not necessarily show that New Horizons can view the hydrogen wall. That is because the ultraviolet light detected by the probes could easily come from another source.

However, the team is still hopeful because Alice — the instrument on board New Horizons that detected the light — is much more sensitive than anything the Voyagers had on board.

“If the ultraviolet light drops off at some point, then New Horizons may have left the wall in its rearview mirror,” wrote the researchers, according to Live Science. “But if the light never fades, then its source could be farther ahead — coming from somewhere deeper in space.”

The finding holds a lot of promise. To follow up on it, New Horizons will scan the cosmos for ultraviolet light twice a year and then report any findings back down to Earth. If anything unusual pops up again, astronomers will instantly know.

“It’s really exciting if these data are able to distinguish the hydrogen wall,” said David McComas, a researcher at Princeton University who was not involved in the new work, in a statement.

Ammonia clouds, jet streams cause Jupiter’s swirling colors

Pressurized magnetic fields 1,800 feet below the surface abruptly cut off the planet’s jet streams.

Jupiter’s iconic horizontal bands and color swirls are caused by strong jet streams or bands of wind that push colorful ammonia clouds across the planet, according to a new study published in The Astrophysical Journal.

The horizontal colored bands for which the giant planet is famous are made up of ammonia in Jupiter’s upper atmosphere, which gives them a variety of colors, including white, yellow, orange, red, and brown.

Unlike Earth, Jupiter has no known solid surface, resulting in the bands diving deeply into its gaseous subsurface of hydrogen and helium.

According to researcher Navid Constantinou of the Australian National University (ANU) Research School of Earth Sciences, Jupiter’s jet streams, which drive the flow of gases around the giant planet’s outer atmosphere, are influenced and shaped by magnetized gases far below the planet’s surface.

NASA’s Juno spacecraft, which has been orbiting Jupiter since July 2016, recently found that the planet’s jet streams extend to a depth of 1,800 miles (3,000 km) before coming to a sudden end.

Without solid geography such as mountains and large landmasses, Jupiter’s jet streams are never modified and therefore stay straight and regular, as opposed to Earth’s jet streams, which are obstructed by surface features that make them wavy and irregular.

Working with Jeff Parker of Lawrence Livermore National Laboratory in Livermore, California, Constantinou created a mathematical model of planetary jet streams based on those of Earth, which drive its climate and weather. They found that Jupiter’s atmosphere, which is composed largely of hydrogen and helium, undergoes heavy pressure beneath the surface that strips electrons from hydrogen and helium molecules, generating electric and magnetic fields.

Pressure from these electric and magnetic fields begins approximately 1,800 miles (3,000 km) beneath the surface, exactly where the jet streams abruptly end.

Movements and patterns seen in surface horizontal bands are influenced by these intense subsurface magnetic fields.

“We think our new theory explains why the jet streams go as deep as they do under the gas giant’s surface but don’t go any deeper,” Parker said.

Studying Jupiter’s atmosphere gives scientists important insights into the general atmospheric flows of planets, Constantinou noted.

Earth’s oldest rocks came from asteroids, study reports

A new study suggests that the oldest rocks on Earth came from ancient meteorite impacts.

A group of researchers from the Curtin University have found evidence that Earth’s oldest rocks once came from meteors traveling through space, according to a new study published in the journal Nature Geoscience.

The theory — which argues that a meteorite bombardment created the ancient stones — states such an event is the only way to explain the temperature and pressure conditions that formed the oldest rocks on our world.

“We believe that these rocks may be the only surviving remnants of a barrage of extraterrestrial impacts which characterized the first 600 million years of Earth’s history,” said lead study author Tim Johnson, a geologist at Curtin University, according to Space.com.

To make the findings, scientists analyzed a 4-billion-year-old rock type — known as Idiwhaa gneiss — in northwest Canada. They looked at the chemical composition of the rocks and then modeled how they first formed. That revealed they came about through low pressures and temperatures that reached 1,650 degrees Fahrenheit.

Those conditions almost never happen under normal circumstances. When temperatures hit those levels, pressures need to be much higher. To explain that, the team turned to meteorites.

They found that in the early days of Earth impacts from space rocks would have been able to raise temperatures enough to melt rocks at the top of the crust without increasing pressure. Though most of the rocks created during that time fell back into Earth’s interior, the Idiwhaa rocks are still around to give insight into that ancient time. 

“The idea of making felsic melts by large or giant impacts seems plausible considering the high-energy nature of these events and the pockmarked ancient surfaces of other inner Solar System planets and moons,” said Balz Kamber, a researcher from Trinity College Dublin who was not involved in the research, according to Phys.org.

Last year’s solar eclipse viewed by record number of Americans

People continued to seek information for months after the eclipse.

The August 21, 2017, “Great American Eclipse” was observed by 216 million or 88 percent of American adults over 18 either in person or online, according to a survey conducted by Jon Miller, director of the International Center for Advancement of Scientific Literacy at the University of Michigan’s (U-M) Institute for Social Research.

Following the event, Americans continued to seek information about it through library visits, online searches, and conversations with their friends, Miller found in his national study, which is available for viewing online.

Miller polled people on the evening of August 21 and continued doing so for the following week. He followed up by surveying some of the same people and some new ones at the end of 2017 and again in February-March of this year.

“What we found was there was a substantial amount of people going online, going to libraries, talking to their friends, trying to figure out what was going to happen with the eclipse before and after the event. To a large extent, scholars have watched what people do before a scientific event but not what they do after. The event can be a stimulus that causes people to look for more information,” he said.

The number of Americans who viewed the total solar eclipse, either directly or electronically, is among the largest to view any public event, including sporting events and entertainment productions.

Of the 21 million adults who traveled to locations in or near the narrow path of totality, respondents engaged in an average of 24 activities seeking information about the eclipse in the two months leading up to the event.

Several months after the eclipse, many people continued to seek information about it and about space-related issues, Miller found in his year-end poll.

Information sought prior to the eclipse most frequently involved searches for safe methods of viewing it, including eclipse glasses and pinhole projectors.

Just three percent of those who observed the eclipse did so as part of an organized group. The majority viewed it with family members, friends, or co-workers.

“This level of public interest and information seeking about a science-oriented event is unparalleled,” Miller emphasized. “It suggests that groups and organizations interested in fostering increased adult interest in science should think about post-event programming to provide resources and a forum for these discussions.”

Last year’s spectacle was the first total solar eclipse visible in the mainland United States since 1979.

Ultrahot Jupiters burn off water in their atmosphere

Scientists have found that ultrahot Jupiters’ burning atmospheres destroy hydrogen and oxygen molecules before they can form water.

Scientists from Arizona State University have discovered the dayside atmosphere of ultrahot Jupiter-like worlds act much more like a star than a planet, according to a new study published in Astrology and Astrophysics.

Such worlds have confused scientists for years because, despite the fact that they are planets, they have extremely improbable compositions. More specifically, their atmospheres contain no water vapor.

This new study sheds light on the celestial bodies and reveals what makes them so unique.

“Interpreting the spectra of the hottest of these Jupiter-like planets has posed a thorny puzzle for researchers for years,” said study co-author Michael Line, a researcher at Arizona State University, according to Science Daily.

In the research, the team found that while ultrahot Jupiters contain the ingredients for water, their dayside temperatures are so high that the molecules are ripped to shreds before they can bond.

Unlike Earth, ultrahot Jupiters have one side that is permanently in day and one side permanently in night. The day side is extremely hot, with temperatures reaching between 3,600 to 5,400 degrees Fahrenheit. That is too hot for the oxygen and hydrogen that make up water to exist.

Researchers made that discovery by using a brown dwarf model and then applying it to the worlds. That revealed it is easy to explain ultrahot Jupiters once they are treated like stars rather than planets.

That finding is important because the bodies have been the subject of research for decades. The new research gives insight into them and could completely alter the way scientists think about planets.

“Our role in this research has been to take the observed spectra of these planets and model their physics carefully,” added Line, according to Phys.org. “This showed us how to produce the observed spectra using gases that are more likely to be present under the extreme conditions. These planets don’t need exotic compositions or unusual pathways to make them.”