For the astronaut shown above, he/she will be fine for now. As long as their space suit is intact, they should not be in any immediate danger of death. However, if their suit were to malfunction for some reason, what would happen next? This has been “explained” before in movies or television shows; but as we all know, those can sometimes be misleading. Instead, let’s look at this situation from a scientific perspective.
First, there have already been studies done on animals to test how long one could survive in a vacuum. For dogs, they would always survive for up to 90 seconds of exposure. However, that number increased drastically for chimpanzees, which could last up to 200 seconds. Of course, both species would lose consciousness quickly, but there did not seem to be any lasting cognitive damage.
With this information, along with general knowledge of space and the human body, we can begin to make some informed guesses as to what would happen to the exposed human in space. In no particular order (or rather, almost all simultaneously), the following events could occur: rapid expansion of gas in the lungs, swelling, unconsciousness, and lack of blood flow. In addition to this, there has only been one person who has ever experienced being inside a vacuum. When asked to describe his last memory prior to losing consciousness, he said that it was the boiling of moisture on his tongue. Although we do not have a definitive answer for our question, we do know for a fact that survival is simply impossible.
243 Ida is a 56 km long asteroid orbiting in the main asteroid belt with a number of notable features. Ida is an S-type asteroid, or stony asteroid, and is mostly composed of rock and iron from accretion during early solar system formation. Ida was a subject of study by the Galileo spacecraft in 1993, and much of what we thought we knew from telescopic observation has been overturned by the closer look provided by the flyby mission.
Ida orbits with a large number of other asteroids in what is known as the Koronis Asteroid Family. This is a collection of objects with similar orbits, which indicates that they likely were formed from the shattered remains of a single larger asteroid that was recently destroyed by an impact. However, the surface of Ida is heavily cratered, indicating that the asteroid is older than originally anticipated, and older than estimates for the Koronis breakup. It was also discovered that Ida has a natural satellite, Dactyl.
Dactyl is the first natural satellite of an asteroid discovered and scientists have sought to explain how the small asteroid with gravity 0.001 times that of Earth’s gravity could hold onto a satellite. With no atmosphere and such low gravity, it is very unlikely that Dactyl was captured by Ida, so it seems likely that Dactyl may have broken off Ida during a large impact, and then settled in a slow orbit around the asteroid. This theory has gained credibility because of the discovery of a relatively recent crater, named the Azzura crater that may be the result of the impact that created Dactyl. Additionally, ejecta blocks, which are large boulders laying on the surface of Ida, have been found primarily on the leading surfaces of the oblong asteroid as it rotates. This suggests that these boulders were ejected from the surface of Ida and then slowly settled back down to be swept up preferentially by leading surfaces of the quickly spinning asteroid.
Much of the information in this blog post came from Cosmic Pinball by Carolyn Somners and Carlton Allen and I would highly recommend reading it for more information about solar system collisions.
In 1994, one year after its discovery, the fragmented remains of Comet Shoemaker-Levy 9 crashed into Jupiter’s upper atmosphere in a sequence of 23 large impacts, each releasing the energy equivalent of 25,000 megatons of TNT, more than one million times as much energy as released by the nuclear bomb dropped on Hiroshima. Orbital analysis between its discovery in 1993 and its demise in 1994 indicates that Shoemaker-Levy 9 experienced a close encounter with Jupiter in 1992, and it is thought that tidal forces due to this close encounter broke apart the loose mass of ice and dust.
The nucleus of a comet is a dirty snowball formed by accretion of hydrogen compounds in the outer solar system early in its formation. These comets are primarily composed of water ice and carbon dioxide ice, and generally are less dense than astronomers would expect, at about 0.6 g/mL. Scientists think that this lower density may be due to comets’ outgassing of material as they partially sublimate during their passes at the inner solar system. The selective melting of material may leave holes and crevices that lower the density of the comet below what we would expect. It is not known how the tidal forces of Jupiter were able to so completely break apart comet Shoemaker-Levy 9, but it is possible that such crevices weakened the internal structure of the comet nucleus.
Regardless of its structure, the energy released by the ice fragments as they plunged into Jupiter’s upper atmosphere at 63 kilometers-per-second was formidable, and the Earth size purple bruises left on Jupiter’s surface served as a reminder of the dangers of solar system objects to any inhabitants of its larger worlds.
Much of the information in this blog post came from Cosmic Pinball by Carolyn Somners and Carlton Allen and I would highly recommend reading it for more information about solar system collisions.
After their launch in 1984, the identical spacecraft Vega 1 and Vega 2 launched from a Russian Proton Rocket for their double mission of flying through the tail of Halley’s Comet and landing scientific payloads on the surface of Venus. In addition to a regular parachuted lander, the Vega spacecraft each carried a 22-kilogram balloon assembly that detached from the main lander during descent and deployed about 50 km above the surface of Venus. Both of these balloons landed on the night side of Venus. With only 60 hours of battery life on the balloons, and with days on Venus clocking in at a lingering 243 Earth days, it would seem that the Vega balloons would never see the daylight side of Venus. However, over the next 60 hours, the balloons were carried to the daylight side of Venus by the hurricane speed winds found in the middle of the three layers of the Venusian atmosphere. According to NASA, the probes measured “the local atmospheric dynamics, pressure, temperature, lightning, illumination levels, and cloud properties over a period of about 46 hours in both the night- and day-side.”
Pictured above is a formerly proposed mission by the ESA to launch another Venus balloon to follow up the Vega missions, but this project has not yet received funding.
April fools! I know I am a day late with this, but I was surprised to find that this was a common thread appearing on my Facebook feed over the weekend. As is common when “news” appears on social media, an “article” was being passed around that seemingly few people even bothered to read. Instead, the headline that Pluto was a planet once again was enough information as they shared it with all of their friends and family. If one bothered to read it, they would quickly (I hope) notice the clear satire in the article. Surprisingly, Pluto was not renamed due to its similarity to the famous Disney character. And no, there is no new category of “hyper-planets”.
Although this article definitely caught my eye, I realized that many people most likely have no idea why Pluto was dropped as a planet in the first place. It all happened during a meeting of the International Astronomical Union (IAU) in August 2006. During this assembly, the world’s most renowned astronomers voted to establish a new set of criteria for being a planet. The list provided below is being quoted directly from this source.
It is in orbit around the Sun.
It has sufficient mass to assume hydrostatic equilibrium (a nearly round shape).
It has “cleared the neighborhood” around its orbit.
Unfortunately, Pluto fails to meet this third requirement. For objects that meet the first two requirements, but fail the third, the new designation “dwarf planet” was created. Therefore, unless a new discovery or another vote by the IAU, Pluto will remain as it is.
The core of the Sun is at such extreme temperature and pressure that in that core hydrogen atoms are constantly fusing into helium and giving off massive amounts of energy. The Sun fuses about 4.25 million metric tonnes of hydrogen every second, which provides a power generation of 3.8 x 10^26 watts. By contrast, the largest power plant on Earth right now is the Three Gorges Dam in China, which produces 2.25*10^10 watts of power. That means that the sun produces more than 1.68 x 10^16 times the energy than the largest power plant on the planet.
That energy is given off by the sun in the form of heat and light that provides a great deal of the available energy on Earth. The solar energy that reaches the surface of the Earth is equal to about 1 kW/m^2. The average American home uses about 901 kWh per month, or about 1.2 kW average power use, which means that (at 100% efficiency) the average home could be powered with just over 1 square meter of solar panels.
That incoming energy is not only utilized by our solar panels, but also by our plants, and by our atmosphere. Our atmosphere is heated by the Sun’s rays, and our plants are fed by the Sun as well. Those plants in turn feed our animals, and our people. The Sun provides all of the energy to sustain life on Earth, and that’s only a small fraction of the energy the Sun produces.
Climate change is a known natural phenomena – for example, the Earth has gone through periods of extreme cold (the Ice Ages) and has always bounced back to the temperatures we know and love today. What isn’t a natural phenomenon is the rapid acceleration of climate change that has been taking place in recent history. Rather than a slow, gradual, natural process spanning thousands of years, recent history has resulted in fast, man-made climate change known as global warming. And contrary to many people’s beliefs, there is overwhelming scientific evidence that this recent period of global warming is directly due to the activities of man. This is due to the massive amounts of carbon dioxide that have been released into the atmosphere due to human activities. As we now know, this carbon dioxide acts to trap heat around the Earth and cause global warming. The diagram shown below clearly demonstrates the massive increase in carbon dioxide over the last 70 years.
In addition to the strong evidence that is the massive increase in carbon dioxide, we can also look at the results we would expect from global warming. A comprehensive list of these visible consequences can be found here! What is certain is that humans are responsible for this sudden uptick in climate change. It is therefore our responsibility to ensure the well-being of our planet for ourselves, as well as our posterity.
Out of all of planets, the one with the highest surface temperature is Venus clocking in at an average of 864 degrees F1. Despite being millions of miles further from the sun than Mercury, Venus still handily beats out Mercury who “only” averages 800 degrees. You probably already know why this is so, but this blog will take a deeper look at the noxious wonder that keeps Venus so warm and gives it its color, its atmosphere. Venus’ atmosphere is made up entirely of carbon dioxide with smaller concentrations of nitrogen and other trace gases such as argon and water vapor. This atmosphere was created when the rocky core of Venus captured surrounding carbon dioxide gas during its formation and is responsible for both the increased temperatures of Venus through the greenhouse effect as well as the increased surface pressure with air weighing 90 times as much on the surface of Venus or the equivalent of diving 3000 feet under the ocean2. Because the atmosphere is so thick with carbon dioxide and is so efficient at trapping heat, nearly all of the hydrogen and oxygen evaporated away leaving Venus a sweltering, toxic wasteland and an example of the worse possible outcomes of uncontrolled Global warming.
Earthlings have often dreamed about life on other planets. Back when people thought life on Mars was possible, Martians were incorporated into a variety of books, cartoons, and comics. Since Venus is Earth’s “sister planet”, many hoped for the possibility of Venusians. Now we know that life on those planets is not possible, but scientists are still searching the universe for signs of habitable planets. Astronomers and scientists have found many extrasolar planets that are in the habitable zones of other solar systems, offering a very promising location for life. However, astronomers have been gathering more data about our own solar system, and we might not have to look beyond our solar system to find other life.
Astronomers have discovered something amazing about several of the jovian moons: they very likely have subsurface salty oceans. Three moons that have these subsurface oceans are large moons of Jupiter: Europa, Ganymede, and Callisto.
Ganymede is a fascinating moon. It is the largest moon in the solar system and is the only moon with its own magnetic field. Scientists studied the aurorae on Ganymede using the Hubble Space Telescope and determined that the fairly stable aurorae indicate a huge salty ocean. However, Ganymede is not the best moon to start looking for life. The ocean exists, but it is far below the moon’s surface, which means it most likely lacks a hydro-thermal system and thus probably lacks life. While Ganymede is still a wonderful place to study, it is not a great place to look for life.
Callisto was originally thought to be a very boring moon, as it was heavily cratered and showed no real signs of geological activity. That changed when the Galileo spacecraft flew by, giving scientists more data that suddenly made Callisto more interesting. Fluctuations in Callisto’s induced magnetic field implied the existence of electrical currents within the moon. With Callisto’s thin atmosphere and rocky surface, these currents are likely to come from a subsurface salty ocean. It’s still unclear whether or not this subsurface ocean can support life.
Europa is probably the most promising of the three moons in terms of supporting life. Europa’s icy surface is young and full of cracks, filled in by dark, icy material, that indicate the surface had been active in the past. When studying some of the linear features on Europa, scientists determined the patterns would fit if the surface moved independently from the rest of the interior. Studies of tidal heating suggest a global subsurface ocean. Like Callisto, fluctuations in Europa’s induced magnetic field indicate electrical currents, likely cause by a salty ocean. Europa’s hot interior could warm the ocean through volcanic vents, providing enough heat to support life.
In the 2020s, the European Space Agency is planning to launch the JUICE (Jupiter Icy Moons Explorer) mission. The spacecraft will visit these moons of Jupiter and study them for more information about their subsurface oceans and the possibility of life.
Image of Tabby Star‘s light blocked by “mega-structures”
Tabby Star is an unsolved and inexplicable mystery, situated 1,500 light years away from us. Tabby star is located at the constellation Cygnus it was named after the lead scientist in the study of this star, Tabetha S. Boyajian. What’s the mystery behind this star? Well, this star has an unusual light fluctuations where 20% of the light emitted by star is blocked by unknown objects. Scientist believe that whatever is blocking the light isn’t a planet because if it were, a planet as big as Jupiter would only obscure this star by the size of 1%.
An astronomer named Jason Wright and some other scientists have proposed that the blockers are most probably parts of megastructures made by an alien civilization called “Dyson Swarm”. Dyson Swarm is a hypothetical structure that is built by advance civilization (purportedly the alien’s), that is said to be intercepting the light energy by star and use them for their energy needs. This fictional-sounding explanations have created so many controversial thoughts from the media especially. Natural explanations aren’t yet to be expected from this phenomena, until the launch of James Webb Space Telescope in 2018.
Well, I don’t usually believe in aliens or stuffs like it, but who knows it could be it? I am excited because alien megastructures sounds like a pretty cool thing to study about.
