Month: January 2019

Long lunar eclipse coincides with Mars opposition

Event will be streamed live online for those in areas where eclipse won’t be visible.

In an unusual astronomical coincidence, the 21st century’s longest total lunar eclipse will occur on the same night as Mars’s opposition, and both reddish objects will appear in the same part of the sky.

A planet is described as being in opposition when it and the Earth are on opposite sides of the Sun.  Full Moons occur when the Moon is in opposition to the Earth. Objects in opposition rise at sunset and remain visible all night, then set at sunrise.

This particular Mars opposition is occurring when the Red Planet is closest to the Earth, so Mars will be at its largest apparent size when viewed through a telescope and will also be significantly brighter than usual.

Both the lunar eclipse and the Mars opposition will occur on Friday, July 27. Just four days later, Mars will be closest to the Earth, at a distance of 35.8 million miles (57.6 million km). An opposition in which a planet is also at its closest point to the Sun is known as a “perhihelic opposition.”

Because the Red Planet has an elliptical orbit, its distance from Earth ranges from a minimum of 34.6 million miles (55.8 million km) to a maximum of 140 million miles (225 million km). In 2003, the two planets came within 34.6 million miles of each other, the closest they had been in 60,000 years.

Friday’s total lunar eclipse will be visible to observers in Africa, the Middle East, southern Asia, Europe, South America, and Australia. Its total phase, during which the Moon appears red or orange, will last an hour and 43 minutes. From beginning to end, including the partial phases, the entire eclipse will last for almost four hours.

The Moon’s reddish color during the total phase of an eclipse is caused by the scattering of sunlight through Earth’s atmosphere. Because the atmosphere does more scattering of shorter light wavelengths, such as green and blue, longer wavelengths, such as red, become most visible.

During this particular eclipse, the Moon will travel through the center of Earth’s umbra, the darkest part of its shadow. It will also be at apogee, the furthest point in its orbit from the Earth, and will therefore take longer to pass through Earth’s shadow. These two phenomena are the reasons why this eclipse will be so long.

Although the eclipse will not be visible from North America, it will be livestreamed online by the website Time and Date Live, Slooh, and Space.com.

Slooh will also host a live cast on the Mars opposition on Thursday night, July 26. Unlike the lunar eclipse, Mars, like the ordinary full Moon, will be visible all night everywhere in the world barring obscuration by clouds.

Scientists trace origin of Martian dust

Similar composition of dust grains around the planet lead researchers to single source.

Mars’s abundant dust comes from one geological formation near the planet’s equator, a 621-mile (1,000-km) region that has undergone billions of years of erosion and may have once been volcanic.

Known as the Medussae Fossae Formation, this large deposit, which continues to erode over time, has been imaged by the HiRISE camera on NASA’s Mars Reconnaissance Orbiter (MRO).

Unlike dust on Earth, which is separated from rock by water, wind, glaciers, volcanoes, and even meteor impacts, dust on Mars has experienced little influence from any of these phenomena. Ancient surface water and moving glaciers had a limited impact on the dust’s movement.

With a much thinner atmosphere than that protecting Earth, Mars experiences more meteor impacts than our planet, but fragments created by meteors are significantly larger than the fine, tiny Martian dust grains.

Led by Lujendra Ojha and Kevin Lewis of Johns Hopkins University, a team of researchers studied the chemical composition of dust grains collected by landers and rovers in various locations on the Red Planet and found a distinct similarity in all the samples.

“Dust everywhere on the planet is enriched in sulfur and chlorine, and it has this very distinct sulfur-to-chlorine ratio,” Ojha noted.

NASA’s Mars Odyssey, which has been orbiting the planet since 2001, found the dust in the Medusae Fossae Formation to have the same abundance and ratio of sulfur and chlorine as the dust studied by the rovers and landers.

“Mars wouldn’t be nearly this dusty if it wasn’t for this one enormous deposit that is gradually eroding over time and polluting the planet, essentially,” Lewis stated.

The Medussae Fossae Formation is the largest known volcanic deposit in the solar system though it has been steadily shrinking due to erosion by the Martian wind.

By measuring the ridges carved by the wind over time, scientists can calculate how much of the region’s dust has eroded over three billion years, enabling them to approximate the current amount of dust on the Red Planet capable of forming a global layer between 6.6 and 39 feet (2-12 meters) thick.

Dust particles can lower ground temperatures on the Martian surface and raise them further up in the atmosphere through absorption of solar radiation. Greater discrepancy between ground and atmospheric temperatures causes stronger winds, which pick up and transport surface dust.

Every few years, regular seasonal dust storms can become global, potentially harming science instruments and their solar panels by getting stuck inside both.

Findings of the study have been published in the journal Nature Communications.

Ocean worlds could be habitable for long periods of time

Climates can be kept stable by processes other than those that occur on Earth.

Water worlds, planets covered with oceans, could be habitable for life for more than a billion years, according to a new study that conducted over a thousand computer simulations.

Until recently, scientists thought that the only planets capable of supporting life are Earth-like worlds that have land and shallow oceans. Planets completely covered in oceans do not cycle minerals and gases, a phenomenon that keeps Earth’s climate stable.

Over very long periods of time, Earth keeps itself cool by pulling atmospheric greenhouse gases into minerals, then warms itself up by releasing the gases back into the atmosphere through volcanic eruptions.

With telescopes growing more powerful, scientists have discovered numerous exoplanets orbiting stars other than the Sun. Many of these are not at all Earth-like, and some are covered in oceans with depths of up to several hundred miles.

On ocean worlds, Earth’s method of maintaining a stable climate would not work, as all the rock is covered by water, which also suppresses volcanoes.

Edwin Kite of the University of Chicago and Eric Ford of Pennsylvania State University decided to research whether ocean worlds might use a different method to maintain climate stability. They turned to a computer simulation that tracked the evolution of thousands of planets over several billion years.

The computer model showed that if planets are in ideal orbits around their parent stars, have the right amount of carbon, begin their lives with sufficient water, and cycle carbon between their atmospheres and oceans in just the right amounts, they can maintain stable climates.

Additionally, the planets cannot have too many minerals and elements dissolved in their oceans, as these would remove atmospheric carbon.

“The surprise was that many of them stay stable for more than a billion years, just by luck of the draw. Our best guess is that it’s on the order of 10 percent of them,” Kite said.

“How much time a planet has is basically dependent on carbon dioxide and how it’s partitioned between the ocean, atmosphere, and rocks in its early years. It does seem there is a way to keep a planet habitable long-term without the geochemical cycling we see on Earth,” he added.

While the simulations were done for planets orbiting Sun-like stars, their results could also apply to those orbiting smaller, dimmer red dwarf stars.

Findings of the study have been published in the Astrophysical Journal.

Most known exoplanets are water worlds, study reports

Scientists have found that most of the exoplanets on record hold quite a bit of water.

A group of international astronomers have found that many exoplanets two to four times the size of Earth have water on their surface, according to new research presented at the Goldschmidt conference in Boston.

Astronomers first uncovered exoplanets orbiting distant starts in 1992. Since that time, scientists have spent years attempting to uncover their composition. The new research — which comes from data collected by the  Kepler Space Telescope and the Gaia mission — shows that many known worlds could be up to 50 percent water.

Such exoplanets are exciting because they could well change the way researchers search for life in the universe.

“It was a huge surprise to realize that there must be so many water-worlds,” said lead researcher Li Zeng, a researcher at Harvard University, according to Science Daily.

Researchers found that almost all of the 4000 confirmed exoplanets on record fall into one of two categories. They either have an average planetary radius that is 1.5 times Earth’s, or they have one that is 2.5 times Earth’s. That distinction helped the team piece together the internal structure of the distant bodies.

Models created from the data showed that exoplanets with a radius 1.5 times Earth’s are generally rocky, while the ones that have radii 2.5 Earth’s are likely water worlds.

Though water is not as common on such places as it is on Earth, and while the surface temperatures are much too hot to support conventional organisms, the exoplanets could still offer new insight into the universe. Researchers plan to continue exploring them and potentially gain more insight into their mechanisms in the future.

That is because the presence of water, regardless of other conditions, always means there is a chance for life. Even so, the team also states that just because a world has water does not mean there is life. More research has to be done on individual world’s before such claims could be made.

“One has to realize that, although water appears to be precious and rarer on Earth and other inner solar system terrestrial planets, it is in fact one of the most abundant substance in the universe, since oxygen is the third most abundant element after hydrogen and helium,” added Zeng, according to Discover Magazine.

Aliens may not be travelling through space – new study reveals limitations of life on ‘super-Earths’

Extraterrestrials on super-Earths may be caged by their planets’ strong gravitational pulls.

A new study places limitations on aliens living on “super-Earths” being able to engage in interstellar travel. “Super-Earth” planets can reach sizes ten times the mass of our own. Their greater mass results in stronger gravitational pulls, making it exceedingly difficult for extraterrestrials to ascend into space, writes Charles Q Choi for Space.com.

Michael Hippke, an independent researcher with the Sonneberg Observatory in Germany researched the difficulty of spaceflight for inhabitants of super-Earths, or exoplanets. According to the study, to launch the equivalent of an Apollo mission, a rocket on a super-Earth would need to have a mass of about 444,000 tons, due to fuel requirements—think of the mass of the Great Pyramid of Giza in Egypt. “On more massive planets, spaceflight would be exponentially more expensive,” Hippke explains.

Scientists previously hypothesized that worlds other than Earth-like ones could offer circumstances suitable for life, possibly being even more habitable because their stronger gravitational pulls would hold thicker atmospheres, better shielding life from harmful cosmic rays. However, Hippke limits this “super-habitability” theory, calculating that the strong gravitational pull of such planets could make it more difficult for extraterrestrials to leave their home.

Hippke calculated the rocket sizes needed to escape a super-Earth 70 percent wider than our planet and 10 times more massive. On such a world, the escape velocity is about 2.4 times greater than on Earth. “Civilizations from super-Earths are much less likely to explore the stars,” Hippke concludes. He believes they would make more “use of lasers or radio telescopes for interstellar communication…” He submitted his findings to the International Journal of Astrobiology.

Mercury likely has dense, thin crust, study reports

A new study shows that Mercury’s crust is roughly 25 percent thinner than previously believed.

Astronomers working at the University of Arizona’s Lunar and Planetary Lab have found new evidence that suggests Mercury’s crust is not as thick as previously thought, according to new research set to be published in the journal Planetary Science Letters.

To make this discovery, the team analyzed data from NASA’s Mercury Surface, Space Environment, Geochemistry and Ranging (MESSENGER) craft. That then enabled them to mathematically calculate the width of Mercury’s crust. Such calculations revealed that the rock is likely both thinner and more dense than previously thought.

Initially, scientists believed that Mercury’s crust measured 22 miles deep. However, the recent research shows that the crust is 16 miles thick. It is likely denser than aluminum as well.

“We know what minerals usually form rocks, and we know what elements each of these minerals contain,” said lead author Michael Sori, a researcher at the University of Arizona, in a statement. “We can intelligently divide all the chemical abundances into a list of minerals. We know the densities of each of these minerals. We add them all up, and we get a map of density.”

This finding is important because it gives credence to the theory that Mercury’s crust came about through volcanic activity. Even so, that does not explain how Mercury’s core — which measures 60 percent of the planet’s volume — is bigger than both the mantle and crust.

While the jury is still out on that, the team behind the research believes that Mercury’s thinness may be the result of massive impacts that stripped away many of its rock formations. There is also a chance solar winds may have taken away parts of the crust and left the planet with a larger core.

Either way, now that scientists are aware of the planet’s crust, they can get a better idea as to how it evolved or shifted over time. Many organizations around the world plan to follow up on the findings by taking a closer look into the distant planet.

For example, the European Space Agency’s BepiColombo mission — which will launch later this year — is set to land on the world in 2025.

“It’s been a long and occasionally bumpy road to this point, and there is still plenty to do until we are ready for launch,” said Ulrich Reininghaus, the BepiColombo project manager who was not involved in the research, according to Tech Times. “But we are extremely pleased to finally move our preparations to the launch site, and are grateful to everyone who has made this possible.”

Astronomers report latest detection of radio bursts coming from space

The recent detection reflects lower frequencies than what astronomers have reported in the past.

Fast Radio Bursts (FRBs) are some of the most explosive events in the Universe. They can generate as much energy as 500 million Suns in milliseconds, and there could be as many as one happening every second, writes Fiona Macdonald for Science Alert. Now, astronomers report detection of another FRB hitting Earth from an unknown source. This particular radio burst falls within the lower end of the spectrum, within the 50 megahertz frequency range, nearly 200 MHz lower than any other signal scientists have detected before. FRBs are incredibly mysterious, astronomers don’t yet know what’s causing them.

Although one of the signals detected has sent out multiple FRBs from the same location—allowing scientists to pinpoint where in the Universes it’s coming from—they still aren’t certain what caused it. Most signals are only detected once, making it difficult for astronomers to determine the source. The recent FRB was detected on July 25, 2018 and reported in The Astronomer’s Telegram. It has been named FRB 180725A, and was caught by an array of radio telescopes in British Columbia, Canada. The Astronomer’s Telegram is a bulletin board of observations posted by accredited researchers, however these observations haven’t been peer reviewed and verified by independent teams. Still, the results make it the first detection of a FRB under 700 MHz. “These events have occurred during both the day and night, and their arrival times are not correlated with known on-site activities or other known sources,” stipulates Patrick Boyle, project manager for the Canadian Hydrogen Intensity Mapping Experiment (CHIME).

Hypotheses abound for the source of FRBs, including black holes, imploding pulsars, and magnetars emitting giant flares to name a few. According to a Harvard physicist, it’s not impossible that FRBs could be engines firing on alien spaceships. While scientists are working to discover the source, they have learned that FRBs cover a spread of frequencies, they seem to be coming from billions of light-years away, and the source of the bursts has to be very energetic. Solving this mystery could help further understanding of the origin of the Universe.

UV light shows which exoplanets may harbor life

A new study shows that UV light is key in providing the building blocks needed for life.

Researchers from the University of Cambridge and the Medical Research Council Laboratory of Molecular Biology have identified a group of exoplanets with the same chemical conditions that may have once allowed life to exist on Earth, according to a new study published in the journal Science Advances.

In the research, the team found that ultraviolet (UV) light sparks a series of chemical reactions that produce the essential building blocks needed to create life.

Using that idea, they then identified multiple planets that both sit inside their star’s habitable zone and get enough UV light from their host star to spark such reactions.

It is those distant worlds where life is most likely be found.

The team began the study by theorizing that cyanide helped life exist on early Earth. They argued that carbon from meteorites slammed into our planet millions of years ago and interacted with nitrogen to create hydrogen cyanide.

The cyanide then rained to the surface, where it reacted with the sun’s UV light and generated the first building blocks for RNA.

After using UV lamps to recreate such reactions in the lab, the team managed to build many of life’s essential elements, including lipids, amino acids, and nucleotides.

From there, researchers ran a series of experiments to see how quickly the mix of UV light, water, and hydrogen cyanide or sulphite ions can create those key building blocks. They then repeated the process without light.

That showed, while stars around the same temperature as our sun are able to create the right amount of light for life’s building blocks, cool stars cannot.

As a result, the team believes the only planets worth searching for life at are ones in the so-called abiogenesis zone — a region where planets get both liquid water and enough light to activate basic chemistry.

“The thing that you know best about any exoplanet system is the star,” lead author Paul Rimmer, an astrochemist at the University of Cambridge, told Space.com. “So, that seemed like a natural thing to start with.”

While only a few known exoplanets sit in that zone, the team hopes future technology will be able to track down more hanging throughout the cosmos.

“This work allows us to narrow down the best places to search for life,” added Rimmer, according to Phys.org. “It brings us just a little bit closer to addressing the question of whether we are alone in the universe.”

New Horizons team to observe stellar occultation from Senegal and Colombia

Data from distant observation will help guide plans for New Year’s flyby.

NASA’s New Horizons team is preparing to view the spacecraft’s second target, Kuiper Belt Object (KBO) Ultima Thule, pass in front of a star less than five months ahead of its scheduled New Year’s flyby.

When Ultima Thule, also known as 2014 MU69, passes in front of or occults a star on August 4, mission scientists will observe the event from two 18.5-mile (30-km) locations in Senegal and Colombia identified by data from the Hubble Space Telescope (HST) as the places on Earth where the KBO will cast its shadow.

Last summer, the mission team observed three occultations, when Ultima Thule passed in front of three separate stars in June and July. Observing from Patagonia and Argentina, the team successfully viewed the event from five separate sites in spite of extreme winter weather.  Data obtained from the event helped mission scientists learn more about the KBO and set the flyby distance at 2,175 miles (3,500 km).

As then, scientists will set up telescopes on various locations along the shadow’s path to observe the occultation, which this year will be viewed from Senegal and Colombia.

“Gathering occultation data is an extremely difficult task. We are literally at the limit of what we can detect with Hubble, and the amount of computer processing needed to resolve the data is staggering,” said Marc Buie of the Southwest Research Institute (SwRI), who is leading the observation team, as he did last year.

“Our team of almost 50 researchers using telescopes in Senegal and Colombia are certainly hoping lightning will strike twice, and we’ll see more blips in the stars. This occultation will give us hints about what to expect at Ultima Thule and help us refine our flyby plans,” he explained.

The observation team is grateful to the governments of Senegal and Colombia, US embassies in both countries, and the French, Senegalese, Colombian, and Mexican astronomy communities for their support in the project, which requires detailed and painstaking preparations.

Ultima Thule is located more than four billion miles from Earth. Like other Kuiper Belt Objects, it is made of pristine materials unchanged from the time the solar system formed.

Based on last year’s occultations, mission scientists determined the KBO is either a binary system of two objects that orbit close to one another or actually touch one another or a two-lobed object. Its size is estimated at 20 miles (30 km) long if it is a single object or nine to twelve miles (15-20 km) long each if it is two objects.

“If the team is successful, the results will help guide our planning for the flyby,” said New Horizons principal investigator Alan Stern, also of SwRI.

 

 

NASA selects first nine commercial crew astronauts

Scheduled for 2019, astronaut launches will be first from American soil, on American vehicles, since 2011.

Nine men and women have been selected by NASA to be the first astronauts to fly on commercial spaceflight vehicles built by Boeing and SpaceX.

Unofficially dubbed the “Commercial Crew Nine,” the group, whose names were announced by the space agency on Friday, August 3, consist of eight NASA astronauts and one who works for Boeing.

Their launches to the International Space Station (ISS) will be the first from US soil since the space shuttle program ended in 2011.

The astronauts were introduced in a public announcement made at NASA’s Johnson Space Center in Houston, Texas.

“This is a big deal for our country, and we want Americans to know that we are back. We’re flying American astronauts on American rockets from American soil,” said NASA Administrator Jim Bridenstine.

SpaceX’s Crew Dragon and Boeing’s CST-100 Starliner will each conduct two inaugural test flights to the ISS. For both companies, the first flights will be un-crewed. SpaceX’s Crew Dragon will launch on a Falcon 9 rocket while Boeing’s CST-100 Starliner will launch on a United Launch Alliance (ULA) Atlas V rocket. Both rockets are reusable.

Target dates for both the un-crewed and crewed launches remain uncertain. SpaceX hopes to launch the un-crewed mission in November of this year and the crewed one sometime next spring. Boeing’s schedule is similar, with the un-crewed launch now planned for either late 2018 or early 2019 and the crewed launch scheduled for mid-2019.

Both first flights were initially scheduled to launch in August 2018 and be followed by crewed launches later this year.

In 2014, NASA awarded SpaceX and Boeing contracts to fly astronauts to the ISS after the two companies won a competition that lasted four years.

One year later, the space agency announced that astronauts Bob Behnken, Eric Boe, Doug Hurley, and Sunita Williams were beginning training with SpaceX and Boeing.

Behnken and Hurley, both veteran NASA astronauts, will be the first to fly on the Crew Dragon, with launch currently scheduled for April 2019.

NASA astronauts Boe and Nicole Aunapu Mann and Boeing astronaut Chris Ferguson will be the first to fly on the Starliner.

Both the Crew Dragon and Starliner will fly two more missions after their crewed test flights. Veteran NASA astronaut Mike Hopkins and newcomer Victor Glover will fly on the next Crew Dragon mission while former ISS commander Williams and newcomer John Cassada will fly on the next Starliner mission.