Imagem Feita Com 8 Frames Com High Dynamic Range Destacando Os Detalhes Da Superfície Da Lua Durante

NGC 6960 (Western Veil nebula) & Horsehead Nebula and the Flame Nebula

by David Wills

Vasculhando a periferia do Sistema Solar, o Telescópio Espacial Hubble da NASA, registrou um pequeno e escuro satélite orbitando o Makemake, o segundo mais brilhante planeta anão congelado, depois de Plutão, localizado no Cinturão de Kuiper.

O satélite, designado de S/2015 (136472) 1 e apelidado de MK 2, é cerca de 1300 vezes mais apagado que o Makemake. O MK 2 foi visto a aproximadamente 20000 km de distância do planeta anão, e tem um diâmetro estimado em 160 km. O Makemake tem cerca de 1400 km de diâmetro. O planeta anão foi descoberto em 2005, e seu nome foi dado em homenagem à divindade da criação dos povos Rapa Nui da Ilha de Páscoa.

O Cinturão de Kuiper é um vasto reservatório de material congelado, resquício da formação do Sistema Solar a cerca de 4.5 bilhões de anos atrás, e o lar de alguns planetas anões. Alguns desses mundos possuem satélites conhecidos, mas essa é a primeira vez que se descobre um objeto companheiro do Makemake. O Makemake é um dos cinco planetas anões reconhecidos pela União Astronômica Internacional.

As observações foram feitas em Abril de 2015 pela Wide Field Camera 3 do Hubble. O Hubble tem uma capacidade única de observar objetos apagados perto de objetos mais brilhantes e uma esplêndida resolução, que permite que os astrônomos possam observar o brilho do satélite do Makemake. A descoberta foi anunciada no dia 26 de Abril de 2016 através de uma circular emitida no Minor Planet Electronic Circular.

A equipe que fez a observação usou a mesma técnica que foi utilizada para observar os pequenos satélites de Plutão em 2005, 2011 e 2012. Algumas buscas anteriores feitas no Makemake não tinham dado resposta alguma. “Nossas estimativas preliminares mostram que a órbita do satélite parece estar de lado, e isso significa que quando você observa o sistema, você pode as vezes perder o satélite de vista, pois ele mergulha no brilho muito maior do planeta anão”, disse Alex Parker, do Southwest Research Institute em Boulder, no colorado, que é o líder da equipe que analisou as imagens das observações.

A descoberta do satélite pode fornecer uma valiosa informação sobre o sistema do planeta anão. Medindo a órbita do satélite, os astrônomos podem calcular a massa do sistema e ter uma ideia sobre a sua evolução.

A descoberta desse satélite também reforça a ideia de que a maior parte dos planetas anões possuem satélites.

“O Makemake é da mesma classe dos raros objetos parecidos com Plutão, então encontrar um satélite ali é muito importante”, disse Parker. “A descoberta desse satélite nos dá também a oportunidade para estudar o Makemake em maior detalhe”.

A descoberta desse satélite só aumenta cada vez mais a semelhança entre Plutão e o Makemake. Ambos os objetos já são conhecidos por serem cobertos por metano congelado. Como foi feito no caso de Plutão, ao se estudar mais a fundo o satélite, será possível revelar a densidade do Makemake, um resultado importante que indicará se a composição bruta de Plutão e do Makemake são também similares. “Essa nova descoberta abre um novo capítulo na chamada planetologia comparativa, uma maneira de se estudar a região externa do Sistema Solar”, disse Marc Buie, líder da equipe também do Southwest Research Institute em Boulder, no Colorado.

Os pesquisadores precisarão de mais observações do Hubble para fazer medidas precisas para determinar se a órbita do satélite é elíptica ou circular. As estimativas preliminares indicam que se o satélite tem um órbita circular, ele completa uma volta ao redor do Makemake a cada 12 dias.

Determinar a forma da órbita do satélite ajudará a responder questões sobre sua origem. Uma órbita circular e apertada do MK 2 indicará que ele foi o produto da colisão do Makemake com outro objeto do Cinturão de Kuiper. Se o satélite tiver uma órbita alongada, é mais provável que ele tenha sido capturado. Ambos os eventos teriam ocorrido a alguns bilhões de anos atrás quando o Sistema Solar era extremamente jovem.

A descoberta, pode também resolver mistérios do próprio Makemake. Estudos anteriores realizados no infravermelho, revelaram que enquanto a superfície do Makemake é inteiramente brilhante e muito fria, algumas áreas aparecem mais quentes que outras. Os astrônomos têm sugerido que essa discrepância pode ser devido ao fato do aquecimento de regiões discretas e escuras da superfície do Makemake. Contudo, a menos que o planeta anão tenha uma orientação especial, essas manchas escuras deveriam fazer o brilho do planeta anão variar substancialmente enquanto ele rotacionasse, mas essa variação no brilho nunca foi observada.

Esses estudos realizados em infravermelho anteriormente, não tinham resolução suficiente para separar o Makemake do MK 2. A reanálise da equipe, com base nas novas observações do Hubble, sugere que boa parte da superfície mais quente detectada anteriormente na luz infravermelha, na realidade, pode ser, simplesmente a superfície escura do seu companheiro, o MK 2.

Existem ainda algumas possibilidades que podem explicar por que o satélite teria uma superfície tão escura, mesmo orbitando um planeta anão que é brilhante como a neve fresca. Uma ideia é que diferente de objetos maiores, como o Makemake, o MK 2 é muito pequeno, de forma que ele não pode gravitacionalmente manter uma crosta congelada e brilhante, que sublima, mudando do sólido para o gás, quando iluminado pelo Sol. Isso faria com que o satélite fosse similar aos cometas e outros objetos do Cinturão de Kuiper, muitos dos quais são cobertos com um material muito escuro.

Quando o satélite Caronte de Plutão foi descoberto, em 1978, os astrônomos rapidamente calcularam a massa do sistema. A massa de Plutão era centenas de vezes menor do que a massa que foi originalmente estimada na época da sua descoberta em 1930. Com a descoberta de Caronte, os astrônomos repentinamente descobriram algo totalmente diferente sobre Plutão. “São esses tipos de medidas que a descoberta de um satélite permite fazer”, concluiu Parker.

Para mais informações sobre o satélite MK 2 do Makemake, e do Hubble, visite:

http://www.nasa.gov/hubble

http://hubblesite.org/news/2016/18

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Fonte:

http://www.nasa.gov/feature/goddard/2016/hubble-discovers-moon-orbiting-the-dwarf-planet-makemake

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Link para o artigo original:

http://pt.slideshare.net/sacani/discovery-of-amakemakeanmoon

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Nessa quarta-feira, dia 27 de Julho de 2016, às 6:00 da manhã, hora de Brasília, o Electrical Support System Processor Unit, ou ESS, da sonda Rosetta será desligado.

O ESS, é a interface usada para realizar, ou pelo menos tentar as comunicações entre a sonda e o módulo Philae, que permanece em silêncio desde 9 de Julho de 2015.

Esse desligamento já é um preparativo e faz parte das ações que serão realizadas para o encerramento da missão da sonda Rosetta na órbita do cometa 67P/Churyumov-Gerasimenko.

A sonda encontra-se a mais de 520 milhões de quilômetros de distância do Sol e já começa a enfrentar uma perda significante de potência.

Para manter a sonda ativa cientificamente pelos próximos 2 meses, é necessário iniciar o desligamento de alguns sistemas.

Como o módulo Philae, não se comunica desde Julho de 2015, e já foi considerado como estando em hibernação eterna, mesmo com a sonda Rosetta passando bem perto do cometa e tentando comunicação, o ESS foi escolhido para ser desligado, encerrando assim de uma vez a missão do módulo Philae.

Descanse em paz Philae.

(via https://www.youtube.com/watch?v=uNbKPaNob0k)

Estudos!

Exercitando Física Matemática!!

From the unique vantage point of about 25,000 feet above Earth, our Associate Administrator of Science at NASA, Dr. Thomas Zurbuchen, witnessed the 2017 eclipse. He posted this video to his social media accounts saying, “At the speed of darkness…watch as #SolarEclipse2017 shadow moves across our beautiful planet at <1 mile/second; as seen from GIII aircraft”. 

Zurbuchen, along with NASA Acting Administrator Robert Lightfoot, Associate Administrator Lesa Roe traveled on a specially modified Gulfstream III aircraft flying north over the skies of Oregon.

In order to capture images of the event, the standard windows of the Gulfstream III were replaced with optical glass providing a clear view of the eclipse. This special glass limits glare and distortion of common acrylic aircraft windows. Heaters are aimed at the windows where the imagery equipment will be used to prevent icing that could obscure a clear view of the eclipse.

Learn more about the observations of the eclipse made from this aircraft HERE.

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Fotografar um buraco negro, é possível? Óbvio que fotografar o interior de um buraco negro, ou o que acontece além do horizonte de eventos, é algo impossível, pois a partir do horizonte de eventos, nada consegue escapar, nem mesmo a luz.

Agora, fotografar o horizonte de eventos é sim algo possível, porém para realizar esse feito seria necessário um telescópio gigantesco, para se ter uma ideia, para fotografar o horizonte de eventos do buraco negro no centro da Via Láctea, seria necessário um telescópio que tivesse, virtualmente o diâmetro do planeta Terra.

E será que isso é possível? Não só é possível, como está pronto para operar.

A iniciativa se chama Event Horizon Telescope, ou Telescópio do horizonte de Eventos.

O objetivo é integrar os grandes radiotelescópios do mundo, e a através de uma técnica chamada de interferometria e assim conseguir observar o horizonte de eventos do buraco negro supermassivo no centro da Via Láctea.

Para quem não sabe, o buraco negro central da Via Láctea, se chama Sagitarius A*, está localizado a cerca de 26 mil anos-luz de distância da Terra, e obviamente nunca foi observado.

O que se tem são indícios de sua existência devido a observação das estrelas ao redor se movimentando de forma muito rápida, o que sugere um objeto extremamente denso no centro.

O seu horizonte de eventos tem cerca de 20 milhões de km, parece muito, mas na distância que ele está não é nada, é só mesmo, um telescópio do tamanho da Terra é capaz de observar.

O EHT usa uma técnica chamada de VLBI (Very Long baseline array interferometry).

Na verdade a técnica consiste em combinar o poder das maiores antenas de rádio telecópios do mundo todos olhando para um mesmo alvo ao mesmo tempo.

Com a recente adição do ALMA ao EHT sua sensibilidade foi extremamente melhorada.

além dos instrumentos, o local onde ficarão armazenados os dados já está pronto esperando a quantidade enorme de informação. A capacidade de armazenamento é equivalente a de 10000 laptops tradicionais.

Além de tudo isso, obviamente o algoritmo que irá fazer a análise dos dados já está bem desenvolvido.

E para ter uma certeza no sucesso do experimento, simulações já foram rodadas levando em consideração as equações de Einstein.

E o efeito que os astrônomos esperam observar é a sombra do buraco negro na matéria subjacente e quando essa sombra acontecer, o horizonte de eventos se tornará proeminente.

Agora a pergunta que não quer parar? Quando teremos essa imagem?

Os astrônomos pretendem fazer a campanha de observação entre 5 e 14 de Abril de 2017, mas devido à complexidade das análises, provavelmente a primeira imagem só fique pronta em 2018, ah, e só para lembrar não tem nada da NASA nisso.

Além obviamente de fazer a imagem do horizonte de eventos, que será algo extraordinário, esse experimento poderá provar mais uma vez a teoria da relatividade de Albert Einstein. Muitos efeitos só provados teoricamente poderão ser testados nessa observação.

E não existe melhor lugar para testar a teoria da relatividade do que o ambiente extremo nas vizinhanças de um buraco negro.

Será que esse ano conseguiremos esse fato extraordinário? vamos aguardar e estarei aqui anunciando para vocês as novidades.

(via https://www.youtube.com/watch?v=NFRk-1yq86Y)

What's That Space Rock?

The path through the solar system is a rocky road. Asteroids, comets, Kuiper Belt Objects—all kinds of small bodies of rock, metal and ice are in constant motion as they orbit the Sun. But what’s the difference between them, anyway? And why do these miniature worlds fascinate space explorers so much? The answer is profound: they may hold the keys to better understanding where we all come from. Here’s 10 things to know about the solar system this week:

This picture of Eros, the first of an asteroid taken from an orbiting spacecraft, came from our NEAR mission in February 2000. Image credit: NASA/JPL

1. Asteroids

Asteroids are rocky, airless worlds that orbit our Sun. They are remnants left over from the formation of our solar system, ranging in size from the length of a car to about as wide as a large city. Asteroids are diverse in composition; some are metallic while others are rich in carbon, giving them a coal-black color. They can be “rubble piles,” loosely held together by their own gravity, or they can be solid rocks.

Most of the asteroids in our solar system reside in a region called the main asteroid belt. This vast, doughnut-shaped ring between the orbits of Mars and Jupiter contains hundreds of thousands of asteroids, maybe millions. But despite what you see in the movies, there is still a great deal of space between each asteroid. With all due respect to C3PO, the odds of flying through the asteroid belt without colliding with one are actually pretty good.

Other asteroids (and comets) follow different orbits, including some that enter Earth’s neighborhood. These are called near-Earth objects, or NEOs. We can actually keep track of the ones we have discovered and predict where they are headed. The Minor Planet Center (MPC) and Jet Propulsion Laboratory’s Center for Near Earth Object Studies (CNEOS) do that very thing. Telescopes around the world and in space are used to spot new asteroids and comets, and the MPC and CNEOS, along with international colleagues, calculate where those asteroids and comets are going and determine whether they might pose any impact threat to Earth.

For scientists, asteroids play the role of time capsules from the early solar system, having been preserved in the vacuum of space for billions of years. What’s more, the main asteroid belt may have been a source of water—and organic compounds critical to life—for the inner planets like Earth.

The nucleus of Comet 67P/Churyumov-Gerasimenko, as seen in January 2015 by the European Space Agency’s Rosetta spacecraft. Image credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

2. Comets

Comets also orbit the Sun, but they are more like snowballs than space rocks. Each comet has a center called a nucleus that contains icy chunks of frozen gases, along with bits of rock and dust. When a comet’s orbit brings it close to the Sun, the comet heats up and spews dust and gases, forming a giant, glowing ball called a coma around its nucleus, along with two tails – one made of dust and the other of excited gas (ions). Driven by a constant flow of particles from the Sun called the solar wind, the tails point away from the Sun, sometimes stretching for millions of miles.

While there are likely billions of comets in the solar system, the current confirmed number is 3,535. Like asteroids, comets are leftover material from the formation of our solar system around 4.6 billion years ago, and they preserve secrets from the earliest days of the Sun’s family. Some of Earth’s water and other chemical constituents could have been delivered by comet impacts.

An artist re-creation of a collision in deep space. Image credit: NASA/JPL-Caltech

3. Meteoroids

Meteoroids are fragments and debris in space resulting from collisions among asteroids, comets, moons and planets. They are among the smallest “space rocks.” However, we can actually see them when they streak through our atmosphere in the form of meteors and meteor showers.

This photograph, taken by an astronaut aboard the International Space Station, provides the unusual perspective of looking down on a meteor as it passes through the atmosphere. The image was taken on Aug. 13, 2011, during the Perseid meteor shower that occurs every August. Image credit: NASA

4. Meteors

Meteors are meteoroids that fall through Earth’s atmosphere at extremely high speeds. The pressure and heat they generate as they push through the air causes them to glow and create a streak of light in the sky. Most burn up completely before touching the ground. We often refer to them as “shooting stars.” Meteors may be made mostly of rock, metal or a combination of the two.

Scientists estimate that about 48.5 tons (44,000 kilograms) of meteoritic material falls on Earth each day.

The constellation Orion is framed by two meteors during the Perseid shower on Aug. 12, 2018 in Cedar Breaks National Monument, Utah. Image credit: NASA/Bill Dunford

5. Meteor Showers

Several meteors per hour can usually be seen on any given night. Sometimes the number increases dramatically—these events are termed meteor showers. They occur when Earth passes through trails of particles left by comets. When the particles enter Earth’s atmosphere, they burn up, creating hundreds or even thousands of bright streaks in the sky. We can easily plan when to watch meteor showers because numerous showers happen annually as Earth’s orbit takes it through the same patches of comet debris. This year’s Orionid meteor shower peaks on Oct. 21.

An SUV-sized asteroid, 2008TC#, impacted on Oct. 7, 2008, in the Nubian Desert, Northern Sudan. Dr. Peter Jenniskens, NASA/SETI, joined Muawia Shaddas of the University of Khartoum in leading an expedition on a search for samples. Image credit: NASA/SETI/P. Jenniskens

6. Meteorites

Meteorites are asteroid, comet, moon and planet fragments (meteoroids) that survive the heated journey through Earth’s atmosphere all the way to the ground. Most meteorites found on Earth are pebble to fist size, but some are larger than a building.

Early Earth experienced many large meteorite impacts that caused extensive destruction. Well-documented stories of modern meteorite-caused injury or death are rare. In the first known case of an extraterrestrial object to have injured a human being in the U.S., Ann Hodges of Sylacauga, Alabama, was severely bruised by a 8-pound (3.6-kilogram) stony meteorite that crashed through her roof in November 1954.

The largest object in the asteroid belt is actually a dwarf planet, Ceres. This view comes from our Dawn mission. The color is approximately as it would appear to the eye. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

7. Dwarf Planets

Don’t let the name fool you; despite their small size, dwarf planets are worlds that are just as compelling as their larger siblings. Dwarf planets are defined by astronomers as bodies massive enough to be shaped by gravity into a round or nearly round shape, but they don’t have enough of their own gravitational muscle to clear their path of other objects as they orbit the Sun. In our solar system, dwarf planets are mostly found in the Kuiper Belt beyond Neptune; Pluto is the best-known example. But the largest object in the asteroid belt is the dwarf planet Ceres. Like Pluto, Ceres shows signs of active geology, including ice volcanoes.

8. Kuiper Belt Objects

The Kuiper Belt is a disc-shaped region beyond Neptune that extends from about 30 to 55 astronomical units – that is, 30 to 55 times the distance from the Earth to the Sun. There may be hundreds of thousands of icy bodies and a trillion or more comets in this distant region of our solar system.

An artist’s rendition of the New Horizons spacecraft passing by the Kuiper Belt Object MU69 in January 2019. Image credits: NASA/JHUAPL/SwRI

Besides Pluto, some of the mysterious worlds of the Kuiper Belt include Eris, Sedna, Quaoar, Makemake and Haumea. Like asteroids and comets, Kuiper Belt objects are time capsules, perhaps kept even more pristine in their icy realm.

This chart puts solar system distances in perspective. The scale bar is in astronomical units (AU), with each set distance beyond 1 AU representing 10 times the previous distance. One AU is the distance from the Sun to the Earth, which is about 93 million miles or 150 million kilometers. Neptune, the most distant planet from the Sun, is about 30 AU. Image credit: NASA/JPL-Caltech

9. Oort Cloud Objects

The Oort Cloud is a group of icy bodies beginning roughly 186 billion miles (300 billion kilometers) away from the Sun. While the planets of our solar system orbit in a flat plane, the Oort Cloud is believed to be a giant spherical shell surrounding the Sun, planets and Kuiper Belt Objects. It is like a big, thick bubble around our solar system. The Oort Cloud’s icy bodies can be as large as mountains, and sometimes larger.

This dark, cold expanse is by far the solar system’s largest and most distant region. It extends all the way to about 100,000 AU (100,000 times the distance between Earth and the Sun) – a good portion of the way to the next star system. Comets from the Oort Cloud can have orbital periods of thousands or even millions of years. Consider this: At its current speed of about a million miles a day, our Voyager 1 spacecraft won’t reach the Oort Cloud for more than 300 years. It will then take about 30,000 years for the spacecraft to traverse the Oort Cloud, and exit our solar system entirely.

This animation shows our OSIRIS-REx spacecraft collecting a sample of the asteroid Bennu, which it is expected to do in 2020. Image credit: NASA/Goddard Space Flight Center

10. The Explorers

Fortunately, even though the Oort Cloud is extremely distant, most of the small bodies we’ve been discussing are more within reach. In fact, NASA and other space agencies have a whole flotilla of robotic spacecraft that are exploring these small worlds up close. Our mechanical emissaries act as our eyes and hands in deep space, searching for whatever clues these time capsules hold.

A partial roster of our current or recent missions to small, rocky destinations includes:

OSIRIS-REx – Now approaching the asteroid Bennu, where it will retrieve a sample in 2020 and return it to the Earth for close scrutiny.

New Horizons – Set to fly close to MU69 or “Ultima Thule,” an object a billion miles past Pluto in the Kuiper Belt on Jan. 1, 2019. When it does, MU69 will become the most distant object humans have ever seen up close.

Psyche – Planned for launch in 2022, the spacecraft will explore a metallic asteroid of the same name, which may be the ejected core of a baby planet that was destroyed long ago.

Lucy – Slated to investigate two separate groups of asteroids, called Trojans, that share the orbit of Jupiter – one group orbits ahead of the planet, while the other orbits behind. Lucy is planned to launch in 2021.

Dawn – Finishing up a successful seven-year mission orbiting planet-like worlds Ceres and Vesta in the asteroid belt.

Plus these missions from other space agencies:

The Japan Aerospace Exploration Agency (JAXA)’s Hayabusa2– Just landed a series of small probes on the surface of the asteroid Ryugu.

The European Space Agency (ESA)’s Rosetta – Orbited the comet 67P/Churyumov-Gerasimenko and dispatched a lander to its surface.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

Eu e minha tia triufamos no curral do Caprichoso! 🤩💙

Are we alone in the universe?

There’s never been a better time to ponder this age-old question. We now know of thousands of exoplanets – planets that orbit stars elsewhere in the universe.

So just how many of these planets could support life?

Scientists from a variety of fields — including astrophysics, Earth science, heliophysics and planetary science — are working on this question. Here are a few of the strategies they’re using to learn more about the habitability of exoplanets.

Squinting at Earth

Even our best telescopic images of exoplanets are still only a few pixels in size. Just how much information can we extract from such limited data? That’s what Earth scientists have been trying to figure out.

One group of scientists has been taking high-resolution images of Earth from our Earth Polychromatic Imaging Camera and ‘degrading’ them in order to match the resolution of our pixelated exoplanet images. From there, they set about a grand process of reverse-engineering: They try to extract as much accurate information as they can from what seems — at first glance — to be a fairly uninformative image.

Credits: NOAA/NASA/DSCOVR

So far, by looking at how Earth’s brightness changes when land versus water is in view, scientists have been able to reverse-engineer Earth’s albedo (the proportion of solar radiation it reflects), its obliquity (the tilt of its axis relative to its orbital plane), its rate of rotation, and even differences between the seasons. All of these factors could potentially influence a planet’s ability to support life.

Avoiding the “Venus Zone”

In life as in science, even bad examples can be instructive. When it comes to habitability, Venus is a bad example indeed: With an average surface temperature of 850 degrees Fahrenheit, an atmosphere filled with sulfuric acid, and surface pressure 90 times stronger than Earth’s, Venus is far from friendly to life as we know it.

The surface of Venus, imaged by Soviet spacecraft Venera 13 in March 1982

Since Earth and Venus are so close in size and yet so different in habitability, scientists are studying the signatures that distinguish Earth from Venus as a tool for differentiating habitable planets from their unfriendly look-alikes.

Using data from our Kepler Space Telescope, scientists are working to define the “Venus Zone,” an area where planetary insolation – the amount of light a given planet receives from its host star – plays a key role in atmospheric erosion and greenhouse gas cycles.

Planets that appear similar to Earth, but are in the Venus Zone of their star, are, we think, unlikely to be able to support life.

Modeling Star-Planet Interactions

When you don’t know one variable in an equation, it can help to plug in a reasonable guess and see how things work out. Scientists used this process to study Proxima b, our closest exoplanet neighbor. We don’t yet know whether Proxima b, which orbits the red dwarf star Proxima Centauri four light-years away, has an atmosphere or a magnetic field like Earth’s. However, we can estimate what would happen if it did.

The scientists started by calculating the radiation emitted by Proxima Centauri based on observations from our Chandra X-ray Observatory. Given that amount of radiation, they estimated how much atmosphere Proxima b would be likely to lose due to ionospheric escape — a process in which the constant outpouring of charged stellar material strips away atmospheric gases.

With the extreme conditions likely to exist at Proxima b, the planet could lose the equivalent of Earth’s entire atmosphere in 100 million years — just a fraction of Proxima b’s 4-billion-year lifetime. Even in the best-case scenario, that much atmospheric mass escapes over 2 billion years. In other words, even if Proxima b did at one point have an atmosphere like Earth, it would likely be long gone by now.

Imagining Mars with a Different Star

We think Mars was once habitable, supporting water and an atmosphere like Earth’s. But over time, it gradually lost its atmosphere – in part because Mars, unlike Earth, doesn’t have a protective magnetic field, so Mars is exposed to much harsher radiation from the Sun’s solar wind.

But as another rocky planet at the edge of our solar system’s habitable zone, Mars provides a useful model for a potentially habitable planet. Data from our Mars Atmosphere and Volatile Evolution, or MAVEN, mission is helping scientists answer the question: How would Mars have evolved if it were orbiting a different kind of star?

Scientists used computer simulations with data from MAVEN to model a Mars-like planet orbiting a hypothetical M-type red dwarf star. The habitable zone of such a star is much closer than the one around our Sun.

Being in the habitable zone that much closer to a star has repercussions. In this imaginary situation, the planet would receive about 5 to 10 times more ultraviolet radiation than the real Mars does, speeding up atmospheric escape to much higher rates and shortening the habitable period for the planet by a factor of about 5 to 20.

These results make clear just how delicate a balance needs to exist for life to flourish. But each of these methods provides a valuable new tool in the multi-faceted search for exoplanet life.  Armed with these tools, and bringing to bear a diversity of scientific perspectives, we are better positioned than ever to ask: are we alone?

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

Chasing Storms at 17,500mph

Flying 250 miles above the Earth aboard the International Space Station has given me the unique vantage point from which to view our planet. Spending a year in space has given me the unique opportunity to see a wide range of spectacular storm systems in space and on Earth. 

The recent blizzard was remarkably visible from space. I took several photos of the first big storm system on Earth of year 2016 as it moved across the East Coast, Chicago and Washington D.C. Since my time here on the space station began in March 2015, I’ve been able to capture an array of storms on Earth and in space, ranging from hurricanes and dust storms to solar storms and most recently a rare thunder snowstorm.

Blizzard 2016

Hurricane Patricia 2015

Hurricane Joaquin 2015

Dust Storm in the Red Sea 2015

Dust Storm of Gobi Desert 2015

Aurora Solar Storm 2015

Aurora Solar Storm 2016

Thunderstorm over Italy 2015

Lightning and Aurora 2016

Rare Thunder Snowstorm 2016

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