NASA’s new exoplanet telescope, the TESS (Transiting Exoplanet Survey Satellite), was launched April 18, 2018 and is expected to find 20,000 exoplanets during its 2 year primary mission. This is huge increase compared to the 3,933 that are currently confirmed. Among these planets will hopefully be multiple rocky planets in the habitable zone, or zone where liquid water can exist. TESS is sensitive enough to see planets a little bigger than Earth for perhaps 1,823 stars and Earth sized ones for 408 of them. In an article by NASA, Lisa Kaltenegger is quoted explaining that “life could exist on all sorts of worlds, but the kind we know can support life is our own, so it makes sense to first look for Earth-like planets,” thus explaining why the data of these planets in the habitable zone are garnering special attention.
A fascinating detail about the TESS satellite is its orbit. It is in a highly elliptical orbit that’s apogee is almost as far away as the moon and perigee that comes as close as 108,000 km (about 3.5 times closer). TESS is in a 2:1 resonance with the moon, meaning that it orbits the Earth twice for every moon orbit, and is timed to be about 90° away from the moon thus minimizing the moon’s interference in TESS’s orbit.
Galileo Galilei discovered many “luminous objects” in 1610 that were orbiting Jupiter. Thought to be stars, it was discovered that they were moons: Io, Europa, Ganymede and Callisto. Ganymede is the largest moon in the Solar System and is even larger than the planet Mercury. It is the only satellite in the Solar System known to possess a magnetosphere, has a thin oxygen atmosphere, and could have an interior ocean. There have been flybys and probes orbiting Jupiter since the 1970s that approach the moon to learn more about it. The most interesting fact to me about Ganymede is its name and mythological reference. It is named for the mythical Greek son of a king who was taken by Zeus, also known as Jupiter, posing as an eagle. On Mount Olympus, Ganymede won the position of cub bearer to the gods, and stayed on also as the favorite companion to Jupiter also known as Zeus. The more you know!
As it currently stands, Earth has no recourse if a large asteroid decides to strike. Something on the scale of the Cretaceous-Paleogene event would devastate humanity. So, how do we protect ourselves against such an impact?
Form international cooperation to further these goals
Have emergency action plans in place for potential impacts
These goals are surprisingly attainable. Technology already exists that could potentially be used to guide asteroids away from Earth. In earlier plans, some spacecraft would be launched at an incoming object to change its course enough to make it miss Earth. Road blocks come in the form of funding, government approval, and cooperation from other space agencies around the world. However, this is a problem that needs to be solved as soon as possible; if we wait until an object is on course to strike Earth, we likely won’t have time to stop it.
Or at least you should remember the battle on Titan (which is an exoplanet based on Saturn’s real-life moon Titan) in Avengers: Infinity War…
In fact, Titan has shown up more than once in the Star Trek series as well as in other famous films, novels, and comics. Why always Titan?
What makes Titan exceptional among more than 150 known moons in the Solar System?
Titan is the largest moon of Saturn and the second largest moon in the solar system—larger than the planet Mercury.
Titan has a radius of about 1600 miles, which only is 2.5 times smaller than the Earth. The largest moon in the Solar System, Jupiter’s moon Ganymede, is only larger by 2 percent.
Titan is the ONLY known moon with a substantial atmosphere in the Solar System.
According to observations from the Voyager space probes, the atmosphere of Titan is thicker and denser than the Earth’s! Its atmosphere is also the only nitrogen-rich dense atmosphere in the Solar System aside from the Earth’s. On Titan, the air is dense enough that you can walk on its surface without a spacesuit. However, you do need an oxygen mask and special suit to protect you from its temperature of -290 °F. Atmospheric methane creates a greenhouse effect, which keeps Titan’s surface from becoming even colder.
Other than the Earth, Titan is the ONLY object in the Solar System known to have liquids on its surface.
Near-infrared radiation from the Sun reflecting off Titan’s hydrocarbon seas (from: Wikipedia)
There are rivers, lakes, and seas of liquid methane and ethane on Titan’s surface. Although the surface of this icy world is covered by a “golden hazy atmosphere,” the Cassini-Huygens mission discovered liquid hydrocarbon lakes in Titan’s polar regions. Titan has an Earth-like liquid cycle, which includes raining, filling of the water body, and evaporation. Scientists also suspect that its volcanoes release water instead of molten rock lava. There is also speculation that Titan has a subsurface ocean of water according to the gravity measurements.
Titan is considered one of the most habitable place in the Solar System.
The information above reveals Titan’s potential for harboring life forms that can survive in the surface hydrocarbon liquids or the subsurface ocean. Although there’s no evidence of life on Titan so far, it is definitely worth further exploration due to its unique features.
Space exploration is something that intrigues us all because, as Star Trek coined many years ago; “Space: the final frontier… To boldly go where no man has gone before”. We’ve traveled to space many time before, with the Apollo 11 moon landing being one of the most famous expeditions. This trip was so famous because it was the first time anyone has ever stepped food on another celestial body other than Earth. However, since then, we have not stepped foot anywhere else. So what is the next place mankind will go? According to Elon Musk and SpaceX, Mars is our next destination. We have already sent objects to Mars, such as the Mars Rover, but now it is time to send people to Mars. SpaceX intends to send send a cargo mission to Mars in 2022, with a second cargo and crew mission in 2024. There are a ton of ethical questions that come with travel like this, but only time will tell of what is to come next.
The sun is a main sequence star, which means it is powered through the process of nuclear fusion. Nuclear fusion is the process of multiple (two or more) nuclei combining to form a completely different nuclei. This process occurs under extreme conditions and releases immense amounts of energy.
The sun, at its core (literally), is just a ball of burning gas. The core of the sun is made up mostly of hydrogen atoms, which are just lone protons, and the heat of the sun cause these hydrogen atoms to fuse together and turn into helium atoms. This process emits a tremendous energy. The heat and light that the sun sends across our solar system is the result of energy radiated from its core.
The sun emits astronomical amounts of energy, and does not destroy the solar system in the process. So, why don’t we try to replicate this power on Earth? Well, fusion power has been an idea since the 1940’s. The issue with it, is that nuclear fusion can only occur under extreme temperature and pressure. The sun does this naturally, but for these conditions to be possible on Earth, it requires a ton of energy. We use electrical energy to create the conditions to produce nuclear energy. Since, these conditions are so difficult to obtain, there is actually a net negative energy output while trying to start the nuclear fusion process. Although it is not practical yet, I am hopeful that one day we will be able to replicate the sun’s energy source, and feasibly have fusion power on Earth.
Pulsars are a kind of neutron star that rotates really rapidly. As they spin about their axis, they shoot off “pulses” or beams of energy. These beams are emitted from their magnetic poles. Pulsars (like all neutron stars) are formed from the collapse of a massive star, and are composed almost exclusively of nuclei (the subatomic particles). As a result, pulsars (and all neutron stars) are super dense – one tablespoon of pulsar (or neutron star) material would weigh about 10 million tons on Earth!
Most importantly, however, pulsars spin really fast. This is mainly what distinguishes them from being a “normal” neutron star. In fact, some pulsars can spin over 500 times in one second. This, combined with the fields of charged particles that surround the pulsar (specifically at the poles) results in the high-energy pulses characteristic of pulsars.
We can use radio telescopes to view pulsars from Earth. Every time that a pulsar’s magnetic pole crosses the plane of our telescope, we will detect a “pulse” of electromagnetic radiation.
What causes static on the radio and white noise on the TV? Why do GPS and phone calls sometimes malfunction? And what if I told you that the very same phenomenon was the cause for the “magical” aurora borealis (Northern lights). As a matter of fact, just one phenomenon can account for all of these events (and more) – cosmic rays.
Cosmic rays are pieces of atoms at fly through the Universe at very high speeds. These “pieces” of atoms could be electrons, protons, neutrons, or parts thereof. We believe that cosmic rays are created by high-energy astronomical events (like the explosion of a star), which shatter atoms into smaller pieces and send those pieces zooming throughout the cosmos.
But why study cosmic rays? Well, because these rays are not light (made up of photons) but actually contain matter from their original source (e.g. a star that exploded). Thus, cosmic rays might offer scientists a method to more directly study such events. If you want to learn more about cosmic rays check out this page!
In Blog 2 I said I’d leave this subject for my next blog, so here it is on its own: what is gravitational lensing? As simply as I can explain it: Gravitational Lensing occurs when the mass of a large stellar group distorts light traveling from behind it towards the viewer. Because light is affected by gravity, massive enough regions to produce this effect often include much more dark matter and energy than baryonic mass (aka “stuff”, as we know it). This picture from the HST shows multiple images of a quasar and a galaxy. The quasar is repeated 5 times and the galaxy 3 as light from them is bent on separate paths about our ‘lens’, which converge like we see them.
Existing near the vacuum of space poses unique instrumentation and life cycle challenges for the Hubble telescope. The sun’s radiation has the potential to corrupt electronic signals or damage components, so many parts must be shielded and redundant systems are required. Without atmospheric regulation, the temperature of an object in orbit such as the HST varies between 200° and -150 ° F as it passes in and out of its body’s shadow. The HST is enveloped in an aluminum shell to disperse radiation and provide insulation. All instruments on board must be able to survive such temperatures, or they must be insulated so that their operating conditions remain satisfactory.
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