The life-cycle of a Sun-like star from protostar (left side) to red giant (near the right side) to white dwarf (far right). Credit: ESO/M. Kornmesser
If you want a picture of how you’ll look in 30 years, youngsters are told, look at your parents. The same principle is true of astronomy, where scientists compare similar stars in different age groups to see how they progress.
We have a special interest in learning how the Sun will look in a few billion years because, you know, it’s the main source of energy and life on Earth. Newly discovered HIP 102152 could give us some clues. The star is four billion years older than the sun, but so close in composition that researchers consider it almost like a twin.
Telescopes have only been around for a few centuries, making it hard to project what happens during the billions upon billions of years for a star’s lifetime. We have about 400 years of observations on the sun, for example, which is a minute fraction of its 4.6 billion-year-old lifespan so far.
Today, we take telescopic observations of the Sun for granted, but the technology only became available about 400 years ago. This picture shows the Sun in H-Alpha, on 01-07-2013, using a Lunt Solar LS60Scope/LS50 Hydrogen Alpha Solar filter. Credit: John Chumack
“It is very hard to study the history and future evolution of our star, but we can do this by hunting for rare stars that are almost exactly like our own, but at different stages of their lives,” stated the European Southern Observatory.
ESO’s Very Large Telescope — guided by a team led by the University of Sao Paulo’s Jorge Melendez — examined HIP 102152 with a spectrograph that broke up the light into various colors, revealing properties such as chemical composition. Around the same time, they scrutinized 18 Scorpii, also considered to be a twin but one that is younger than the sun (2.9 billion years old)
So what can we predict about the Sun’s future? One thing puzzling scientists has been the amount of lithium in our closest stellar companion. Although the Big Bang (the beginning of the universe) created hydrogen, helium and lithium, only the first two elements are abundant in the Sun.
Periodic Table of Elements
HIP 102152, it turns out, also has low levels of lithium. Why isn’t clear yet, ESO notes, although “several processes have been proposed to transport lithium from the surface of a star into its deeper layers, where it is then destroyed.” Previous observations of young Sun-like stars also show higher levels of lithium, implying something changes between youth and middle age.
The elder twin to our Sun may host another discovery: there could be Earth-sized planets circling the star. Chemical properties of HIP 102152 show that it has few elements that you see in meteorites and rocky planets, implying the elements are “locked up” in bodies close to the star. “This is a strong hint that HIP 102152 may host terrestrial rocky planets,” ESO stated.
Better yet, separate observations showed that there are no giant planets close to the star — leaving room for Earth-sized planets to flourish.
Determining weather patterns in exoplanet atmospheres – hundreds to thousands of light years away – is extremely difficult. However, given that it may be one of our best ways to truly characterize these alien words, it’s a challenge astronomers have accepted willingly.
Most models have a very simple foundation, necessarily eliminating the complex physics that is difficult to incorporate and analyze. Recently, a team led by Dr. Konstantin Batygin of Harvard University, added one more parameter to their models, drastically changing their results.
The punch line is this: the inclusion of magnetic fields significantly changes, and actually simplifies, the atmospheric circulation of hot Jupiters.
Hot Jupiters orbit dangerously close to their host stars, roasting in stellar radiation. But they are also tidally locked to their host stars – one hemisphere continually faces the star, while one continuously faces away – creating a permanent dayside and a permanent nightside.
One would expect the temperature gradient between the dayside and the nightside to be very high. However, various weather patterns play a role in strongly decreasing this temperature gradient. As an example, we now know that clouds may significantly decrease the temperature of the dayside.
Dr. Batygin’s team analyzed magnetic effects within atmospheric circulation. “The case of hot Jupiters is quite peculiar,” she told Universe Today. “The atmospheres of hot Jupiters have temperatures that reach up to 2000 Kelvin, which is hot enough to ionize trace Alkali metals such as potassium and sodium. So the air on hot Jupiters is actually a weakly conducting plasma.”
Once the alkali metals have been ionized – stripped of their electrons – the upper atmosphere contains all of those charged particles and becomes a plasma. It is then electrically conductive and magnetic effects must be taken into account.
While the underlying physics is pretty complex (with nearly 40 multi-lined equations in the paper alone), the introduction of magnetic effects actually simplified the model’s outcome.
In the absence of magnetic fields, the upper and lower atmospheres feature two distinct patterns of circulation. The upper atmosphere consists of winds blowing away from the dayside in all directions. And the lower atmosphere consists of zonal flows – the bands of color on Jupiter. The zonal flows move parallel to lines of latitude in an east-west fashion. Each moves in a different direction than the one above and below it.
“Upon introducing magnetic fields, fancy dayside-to-nightside flows are quenched and the entire atmosphere circulates in an exclusively east-west fashion,” explains Dr. Batygin. The upper atmosphere resembles the lower atmosphere – zonal flows dominate.
Throughout these models, Dr. Batygin et al. assumed a magnetic field aligned with the rotation axis of the planet. Future work will include a closer look at the effect of a more complicated geometry. The team also intends to extend these results to hotter atmospheres, where magnetic fields will slow the rate of these zonal flows. According to Dr. Batygin, “this has potentially observable consequences and we hope to elucidate them in the future.”
These results will be published in the astrophysical journal (preprint available here).
The central peak of Bullialdus crater (Credit: NASA/GSFC/Arizona State University)
Scientists have detected magmatic water — water that originates from deep within the Moon’s interior — on the surface of the Moon. These findings represent the first such remote detection of this type of lunar water, and were arrived at using data from NASA’s Moon Mineralogy Mapper (M3) carried aboard India’s Chandrayaan-1 lunar orbiter.
The discovery represents an exciting contribution to the rapidly changing understanding of lunar water according to Rachel Klima, a planetary geologist at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., and lead author of the paper, “Remote detection of magmatic water in Bullialdus Crater on the Moon” published in the August 25 issue of the journal Nature Geoscience.
Chandrayaan-1, India’s first mission to the Moon, entered lunar orbit on Nov. 8, 2008
“For many years, researchers believed that the rocks from the Moon were ‘bone dry’ and that any water detected in the Apollo samples had to be contamination from Earth,” said Klima, a member of the NASA Lunar Science Institute’s (NLSI) Scientific and Exploration Potential of the Lunar Poles team. “About five years ago, new laboratory techniques used to investigate lunar samples revealed that the interior of the Moon is not as dry as we previously thought. Around the same time, data from orbital spacecraft detected water on the lunar surface, which is thought to be a thin layer formed from solar wind hitting the lunar surface.”
“This surficial water unfortunately did not give us any information about the magmatic water that exists deeper within the lunar crust and mantle, but we were able to identify the rock types in and around Bullialdus crater,” said co-author Justin Hagerty, of the U.S. Geological Survey. “Such studies can help us understand how the surficial water originated and where it might exist in the lunar mantle.”
LRO image of the 60-km Bullialdus crater (NASA/GSFC/Arizona State University)
M3 (pronounced “M-cube”) fully imaged the large impact crater Bullialdus in 2009. “It’s within 25 degrees latitude of the equator and so not in a favorable location for the solar wind to produce significant surface water,” Klima explained. “The rocks in the central peak of the crater are of a type called norite that usually crystallizes when magma ascends but gets trapped underground instead of erupting at the surface as lava. Bullialdus crater is not the only location where this rock type is found, but the exposure of these rocks combined with a generally low regional water abundance enabled us to quantify the amount of internal water in these rocks.”
After examining the M3 data, Klima and her colleagues found that the crater has significantly more hydroxyl — a molecule consisting of one oxygen atom and one hydrogen atom — compared to its surroundings. “The hydroxyl absorption features were consistent with hydroxyl bound to magmatic minerals that were excavated from depth by the impact that formed Bullialdus crater,” Klima writes.
The internal magmatic water provides information about the Moon’s volcanic processes and internal composition, Klima said. “Understanding this internal composition helps us address questions about how the Moon formed, and how magmatic processes changed as it cooled. There have been some measurements of internal water in lunar samples, but until now this form of native lunar water has not been detected from orbit.”
“This impressive research confirms earlier lab analyses of Apollo samples, and will help broaden our understanding of how this water originated and where it might exist in the lunar mantle.”
You might be surprised to know that I have an opinion. People often ask me for it, but tend not to give it. But I was getting into a discussion with Amy Shira Teitel from Vintage Space about the priorities of humans versus robots for space explorations and offered up this opinion.
On matters of humans versus robots exploring space, this is what I think. Both, with different agendas.
Opinion: Should Robots or Humans Explore Space?
What’s the best way to explore the Solar System? Should we send humans, or robots? Robots are durable and replaceable, while humans are creative and flexible.
Space advocates line up on both sides of this discussion, and the debate can get heated.
Really heated.
Don’t be fooled. This whole conversation is a red herring.
We shouldn’t have to choose between human space exploration and robotic science, and it is absolutely ridiculous that the funding for it comes into a single agency.
The future of humanity will depend on us learning to live in space; to get off this planet and spread to the rest of the Solar System. The longer we remain trapped on this planet, the greater risk we face from a global catastrophe; whether it’s from an asteroid strike or a global plague.
We, as a species, are keeping all our eggs in one basket,
I don’t need to tell you how important science is. Our modern marvels are a direct result of the scientific method. The fact that you can even see this video (well, or read this article) should be all you need to know about the importance of science.
And we have no idea what we’ll find out there in space when we go exploring.
Were it up to me, I’d separate space exploration into two agencies, with completely different agendas and budgets.
On the science side, we need a fleet of robotic spacecraft and satellites continuously launching into space. We’d settle on a rugged, multi-purpose vehicle, which carries a variety of payloads and scientific instruments.
Curiosity Rover snapped this self portrait mosaicThe Curiosity Rover was an amazing success, and NASA should just keep building more rovers exactly like it. Give it cameras, grinders and scoops, but then keep the instruments open to the scientific community. Every two years, another identical rover will blast off to the Red Planet, hurling a fresh set of instruments to a new location.
Let’s send a rover and an orbiter every two years to Mars, and similar probes to other worlds, only the scientific instruments would need change. In a few years, there would be versions of the exact same spacecraft orbiting planets, asteroids and moons.
Over time, our observation of the Solar System would extend outward like a nervous system, gathering scientific knowledge at a terrific rate.
Neil Armstrong and Buzz Aldrin plant the US flag on the Lunar Surface during 1st human moonwalk in history – exactly 44 years ago on July 20, 1969 during Apollo 1l mission. Credit: NASAFor human space exploration, we need to learn to live in space in increasingly complex ways: low Earth orbit, lunar orbit, on the lunar surface, on Mars, on asteroids, at Saturn, in the Lagrange points, et cetera.
Remember the Gemini program back in the 1960s? Each mission was an incremental step more complicated than the previous one. On one mission, the goal was just to learn if humans could survive in space for 14 days. In another mission, the goal was just to learn how to dock two spacecraft together.
This gave NASA the knowledge they needed to attempt an ambitious human landing on the Moon.
Chris Hadfield in the Cupola of the ISS. Credit: NASAInstead of flying in low-Earth orbit for decades, our human space program could continuously advance our knowledge of what it takes to survive – and eventually thrive – in space. If NASA investigates the technologies that the private sector considers too risky to invest in, it will help jump start space exploration.
In this modern era of budget cuts, it breaks my heart that people are forced to choose between space science and human exploration.
It shouldn’t be this way. They have almost nothing in common.
Let’s do science, because science is important.
And let’s put humans in space, because humanity is important.
We've been here before... (All article images and bad photoshopping courtesy of the author).
It’s hard to believe that it’s been with us for a decade now.
Ten years ago this week, the planet Mars reached made an exceptionally close pass of the planet Earth. This occurred on August 27th, 2003, when Mars was only 56 million kilometres from our fair planet and shined at magnitude -2.9.
Such an event is known as opposition. This occurs when a planet with an orbit exterior to our own reaches a point opposite to the Sun in the sky, and rises as the Sun sets. In the case of Mars, this occurs about every 2.13 years.
But another myth arose in 2003, one that now makes its return every August, whether Mars does or not.You’ve no doubt gotten the chain mail from a well-meaning friend/relative/coworker back in the bygone days a decade ago, back before the advent social media when spam was still sorta hip. “Mars to appear as large as the Full Moon!!!” it breathlessly exclaimed. “A once in a lifetime event!!!”
Though a little over the top, the original version did at least explain (towards the end) that Mars would indeed look glorious on the night of August 27th, 2003 … through a telescope.
Mars during the historic opposition season of ’03.
But never let facts get in the way of a good internet rumor. Though Mars didn’t reach opposition again until November 7th 2005, the “Mars Hoax” email soon began to make its rounds every August.
Co-workers and friends continued to hit send. Spam folder filled up. Science news bloggers debunked, and later recycled posts on the silliness of it all.
Now, a decade later, the Mars Hoax seems to have successfully made the transition over to social media and found new life on Facebook.
How Mars really appears next to the Moon: Mars as seen during a close conjunction with the Moon on July 17th, 2003. Mars was 20 arc seconds in size at the time, leading up to the August 2003 opposition. Image courtesy of Rick Stankiewicz, used with permission.
No one knows where the Mars Hoax meme goes to weather the lean months, only to return complete with all caps and even more exclamation points each and every August. Is it the just a product of the never ending quest for the almighty SEO? Are we now destined to recycle and relive astronomical events in cyber-land annually, even if they’re imaginary?
Perhaps, if anything there’s a social psychology study somewhere in there, begging the question of why such a meme as the Mars Hoax endures… Will it attain a mythos akin to the many variations of a “Blue Moon,” decades from now, with historians debating where the cultural thread came from?
Here are the facts:
-Mars reaches opposition about every 2.13 Earth years.
-Due to its eccentric orbit, Mars can vary from about 56 million to over 101 million kilometres from the Earth during oppositions.
-Therefore, Mars can appear visually from 13.8” to 25.1” arc seconds in size.
-But that’s still tiny, as the Moon appears about 30’ across as seen from the Earth. You could ring the local horizon with about 720 Full Moons end-to-end, and place 71 “maxed out Mars’s” with room to spare across each one of them!
-And although the Full Moon looks huge, you can cover it up with a dime held at arm’s length…. Try it sometime, and amaze your email sending/Facebook sharing friends!
–Important: Mars NEVER gets large enough to look like anything other than a star-like point to the naked eye.
Reality check… how Mars actually appears compared to the Moon as seen during a close conjunction in 2012.
-And finally, and this is the point that should be getting placed in all caps on Facebook, to the tune of thousands of likes… MARS ISN’T EVEN ANYWHERE NEAR OPPOSITION in August 2013!!! Mars is currently low in the dawn sky in the constellation Cancer on the other side of the Sun. Mars won’t be reaching opposition until April 8th, 2014, when it will reach magnitude -1.4 and an apparent size of 15.2” across.
Still, like zombies from the grave, this myth just won’t die. In the public’s eye, Mars now shines “As big as” (or bigger, depending on the bad hyperbole used) as Full Moon now every August. Friends and relatives hit send, (or these days, “share” or “retweet”) observatories and planetariums get queries, astronomers shake their heads, and science bloggers dust off their debunking posts for another round. Hey, at least it’s not 2012, and we don’t have to keep remembering how many “baktuns are in a piktun…”
What’s a well meaning purveyor & promoter science to do?
Feed those hungry brains a dose of reality.
There are real things, fascinating things about Mars afoot. We’re exploring the Red Planet via Mars Curiosity, an SUV-sized, nuclear powered rover equipped with a laser. The opposition coming up next year means that the once every 2+ year launch window to journey to Mars is soon opening. This time around, the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission and, just perhaps, India’s pioneering Mars Orbiter Mission may make the trip. Launching from Cape Canaveral on November 18th, MAVEN seeks to answer the questions of what the climate and characteristics of Mars were like in the past by probing its tenuous modern day atmosphere.
The circumstances for the oppositions of Mars from 2001 to 2029.
And as opposition approaches in 2014, Mars will again present a fine target for small telescopes. As a matter of fact, Mars will pass two intriguing celestial objects next month, passing in front of the Beehive cluster and — perhaps — a brightening Comet ISON. More to come on that later this week!
And it’s worth noting that after a series of bad oppositions in 2010 and 2012, oppositions in 2014 and 2016 are trending towards more favorable. In fact, the Mars opposition of July 27th, 2018 will be nearly as good as the 2003 approach, with Mars appearing 24.1” across. Not nearly as “large as a Full Moon” by a long shot, but hey, a great star party target.
Will the Mars Hoax email enjoy a resurgence on Facebook, Twitter or whatever is in vogue then? Stay tuned!
Red sprite lightning seen over Nebraska on August 12, 2013. Credit and copyright: Jason Ahrns.
When we first checked in with graduate student and astrophotographer Jason Ahrns earlier this month, he had the chance to be part of an observing campaign to try and photograph red sprite lightning from the air. Using a special airplane from the National Center for Atmospheric Research’s Aircraft Facility in Boulder, Colorado, Jason was part of a team that used high-speed video cameras and digital still cameras to learn more about this mysterious lightning. They flew over the central part of the US, such as over Colorado, Nebraska, and Oklahoma.
Named for the mythological sprites, which were known for being elusive, this lightning flashes quickly at high altitudes of 65-75 km (40-45 miles), but often as high as 90 km (55 miles) into the atmosphere. They are difficult to see from the ground, thus this airborne observing campaign.
Here are more images and video (some at 10,000 frames per second!) taken by Jason and his team:
Red sprite lighting, taken on August 12, 2013 over Red Willow County, Nebraska, US as part of a sprite observing campaign. Credit and copyright: Jason Ahrns.
Jason said on his blog, documenting the observing campaign, that “Most of what we saw were C-sprites, short for ‘Column sprites’ or ‘Columnar sprites’ – it just refers to their shape as tall, single columns.”
Sprites appear as luminous reddish-orange flashes, and sometimes look like jellyfish with “legs” that reach down into the clouds. Besides the columnar shapes, they also can be shaped like carrots and crowns, but why they take different shapes is unknown. They are thought to be triggered by the discharges of positive lightning between an underlying thundercloud and the ground. They were discovered by accident in 1989 when a researcher studying stars was calibrating a camera pointed at the distant atmosphere where sprites occur.
Sprite lighting, taken on August 12, 2013 over Red Willow County, Nebraska in the US. Credit and copyright: Jason Ahrns.
Above is an image, and below is the video of the same sprite slowed down by about 500 times:
UV image of Titan acquired by Cassini on April 13 (NASA/JPL-Caltech/SSI)
As high summer slowly but steadily approaches on Saturn, Cassini is opening a window to the seasonal changes that occur not only on the ringed planet but also its moons. Here we can see a dark band developing around Titan’s north polar latitudes, a “fancy collar” made visible in ultraviolet wavelengths.
Polar collars have previously been seen by both Hubble and Voyager 2, and in fact a southern version was observed by HST 5 years after the planet’s 1995 equinox.
This summer collar is thought to be part of a seasonal process, related to the migration of upper-level haze material within Titan’s atmosphere.
Source: CICLOPS (Cassini Imaging Central Laboratory for OPerationS)
A crater on Mercury at the edge of the larger Oskison crater located in the plains north of Caloris basin. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Permanently shadowed craters on the moon or Mercury are one of the most exciting locations to search for water. Because the walls of these craters protect certain spots inside from the rays of the sun, it’s quite possible for ice to lurk inside of there.
We’ve found ice on so-called airless worlds because of this trick of geometry. So how about exploring them? What’s the best way to do so?
The NASA Innovative Advanced Concepts office suggests using TransFormers to get inside these places. No, not the awesome robots you see in the movies, but still something that has a certain degree of complication: “multifunctional platforms that can change their shape and function”, according to the agency.
NASA’s TransFormers mission concept as it could be deployed on Mercury. Credit: NASA Innovative Advanced Concepts
Like the iconic science fiction heroes, however, the TransFormers would be able to unfold and change their shape. These machines could relay information between a rover and an orbiting satellite, or reflect solar energy on to a target (say, a solar-powered rover).
The challenge with putting a rover in a permanently shadowed crater is figuring out how to power it. Nuclear power sources have special handling considerations during preparation and launch that must be taken into account for safety reasons. Solar power, however, would not be possible in these craters given there is no sunlight.
Putting a TransFormer at the crater’s edge, however, could make the environment a friendly one for a rover powered by the sun. It could reflect light inside and provide a power source for the rover to keep moving.
Solar-panelled rovers are already used on Mars. Here, the Spirit rover’s solar panels were covered with dust until a gust of wind blew it off in 2006. Credit: NASA.
And once that rover starts running around, it would have immense scientific benefits, NASA stated.
“For example, water found in the permanently shadowed areas of craters on the Moon or Mercury can reveal clues about planetary formation and history, and could be used as a resource for astronauts,” the agency wrote.
This could even be extended to the Red Planet, which offers the enticing possibility of stumbling across life.
“Cave exploration on Mars offers the possibility of finding extraterrestrial life; furthermore, caves are time capsules preserving geochemical traces and may safely shelter future human explorers.”
Neil Armstrong in the LM after his historic moonwalk (NASA)
Apollo 11 moonwalker Neil Armstrong died on Aug. 25, 2012 at age 82, and NASA has posted a video tribute with an original song “Tranquility Base” by songwriter Eric Brace. Fittingly, the video starts with a 1960’s era television set showing the first Moon landing… were you watching on a TV like that on July 20, 1969 when Neil took those first steps on the Moon?
The song begins:
“Tell me Neil, what you were thinking
With all of us watching you on the TV
Taking small steps and giant leaps and planting the flag
In a place no one had been.”
A beautiful display of the aurora borealis on June 6 this year. The line of light is the International Space Station; an airplane is off to the left. Credit: Bob King
As an amateur astronomer, two of the most frequently questions I’m asked are “When is the best time to see the aurora borealis and where is the best place?” In terms of place, two locations comes to mind: Churchill, Manitoba and Tromso, Norway. But until such time as the transporter is invented, most of us will be staying closer to home. The simple answer is north and the farther north the better.
As for the time, in the northern border states of the US, auroras occur fairly regularly around the time of solar maximum, when the sun peaks in storm activity. The current solar cycle tops out this summer and fall, so your chances at seeing northern lights are far better now than a year and a half ago when solar activity saw a steep decline during a protracted minimum.
