On March 24, 1993, a comet was discovered by Eugene & Carolyn Shoemaker and David Levy. It was the ninth comet that the the three had collaborated to discover, thus it was dubbed “Shoemaker-Levy 9”. However, as they soon discovered, this was no ordinary comet; it was a fragmented one that had been captured and was on a collision course with Jupiter. Scientists eagerly anticipated the impacts of the fragments, which were ascertained to take place between July 16 and July 24th of 1994.
The impacts were massive, and created fireballs which lit up infrared telescopes around the world. The marks left by the collisions were present for months and were the darkest spots to ever be observed on Jupiter.
For more on the impacts, including media coverage, images, and scientific conclusions, read what I read at Ron Baalke’s NASA site on the impact. Baalke’s site was one of the most influential in the history of the internet, and helped the world to recognize the potential that this new information-sharing medium held.
Pictured: the impact of SL9 on the bottom left of the planet. The bright object on the right is the satellite Io. Source
Do you love astronomy? Do you also love ice skating? (I’m looking at you, Dr. G..) What if I told you that you could have the best of both worlds? You can(!), albeit approximately 4.2 AU away from Earth.
Enter Europa, Jupiter’s icy sixth (both largest and closest) moon.
Pictured: tracks from Jupiter’s ice skates
Europa is an extremely young moon despite being the second extraterrestrial moon ever discovered, and as such features a liquid water ocean beneath the icy crust, and a layer of volcanic activity beneath the ocean. In addition to its composition, Europa also has several quirky features such as its lineae on its surface, the massive water plumes it fires into space, and an (extremely thin) oxygenated atmosphere. It is this unique composition and its other quirks which give scientists hope that there may be extraterrestrial life here in our solar system beneath the icy surface of Europa.
Currently NASA is investigating the feasibility of landing a probe on Europa, and there are multiple scheduled missions that will collect data on the moon without actually landing on it.
Meanwhile, I’m going to start learning how to ice skate.
Pictured: an artist’s depiction of Voyager 1, also known as one of the lucky ones. Sometime around 2025, however, it(s power supply) too shall come to pass, and it will die a free probe – more on that later. Source
Bad news: your favorite space probe has been deactivated or worse – its power ran out. What’s the next step? For us as humans, tears for what we’ve lost but ultimately, hope – as long as the government (or Elon Musk) cares, more things will be shot into space. For the space probe, well, that can depend on the mission. There are three main fates for wayward probes: orbit, impact, and jailbreak escape from the solar system.
Orbit
By and large, the primary fate which space probes meet (other than failure to escape the Earth’s gravity – I’m looking at you, early Soviet probes and no-longer-early Russian probes) is that of orbit, be it around the Sun or around other solar system objects. However, probes orbiting other planets or moons will eventually…
Impact
The same civilization which derives viewing pleasure from this also has no qualms about crashing some of its most sophisticated technological achievements into other planets. While all artificial objects in orbit around planets or moons will fall eventually, sometimes we take matters into our own hands by smashing probes into comets or even the moon – for the sake of knowledge, of course! But although impact is certainly more glamorous than a slow death orbiting the Sun, it can’t hold a candle to…
Escape!
Among all the objects mankind has ever constructed, from Lamborghinis to Pintos, from Yeezys to your dad’s flip-flops, only one has escaped (the oppression of) our solar system: the Voyager 1 probe, which was launched on 5 September 1976 and is still somehow transmitting data back to Earth. Also on the way out of the solar system (but not quite out yet) are two derelict Pioneer probes (10 and 11), launched in 1972, Voyager 2 (also launched in 1976), and the New Horizons spacecraft, which was launched in 2006, in addition to four rocket boosters and two counterweights from New Horizons. The Voyager craft and Pioneer craft each carry messages to any extra terrestrial life that may encounter the probes in the future. Below is a video about Voyager 1 crossing into interstellar space.
You measure this kind of ring in candelas instead of carats. Image
A solar eclipse, which is the only acceptable way to propose to an astronomer, is a fairly uncommon event which occurs when the Moon passes between the Earth and the Sun. Although the Moon is much smaller than the Sun, it is able to completely block the Sun because it is much closer to the Earth. There are four types of solar eclipses: total, partial, annular, and hybrid.
A total solar eclipse occurs when the Moon completely blocks sunlight from reaching a part of the Earth. The shadow created by the Moon is called an umbra, and it covers a small portion of the Earth, traveling along the ground as the Earth rotates. The amount of time that the Sun is completely blocked is referred to as the period of totality.
A total solar eclipse, photograph courtesy of NASA
A partial solar eclipse takes place when the Moon partially blocks the Sun’s light from reaching the Earth. In the case of partial eclipses, the Moon’s shadow is a penumbra, and can be visible across large portions of the Earth’s surface. Even during total eclipse events, most areas will only experience a partial eclipse.
A partial solar eclipse, photograph courtesy of NASA
An annular solar eclipse is an eclipse which occurs when the Moon is at or near its farthest point from the Earth in its orbit (the Moon varies in distance from the Earth, fluctuating between 362,600 km and 405,400 km away from the Earth), causing the sun to not be fully obscured by the Moon. This occurs because the umbra is projected no longer than 379,000 km from the Moon. During these eclipses, an annulus, or ring of fire, appears around the Moon.
An annular solar eclipse, photograph courtesy of ABC News
Hybrid solar eclipses are created when the Moon’s orbital distance is near the umbra’s distance limit. During a hybrid eclipse, the Moon at first is too far away from the Earth to create a total eclipse, causing an annular eclipse. Further along the eclipse path, the Moon draws closer to the Earth, leading to a total eclipse. Hybrid eclipses are the rarest form of eclipse.
As always, please reply with any questions and I will respond ASAP in order to earn the conversation bonus.
Stars on our Helmets, Stars in the Sky 
