Earth vs. Theia! First and Last Round!

I have a thing for stuff that is outrageous, different and intriguing. Greek Gods, bizarre happenings in space, and archaic events? Yes, please! So, I just recently learned about how Moon was the result of an ancient collision between old Earth (or some people call it Gaia) and another theoretical planet named Theia 4.5 billion years ago. Also known as The Big Splash or The Theia Impact, the historical collision was believed to be the origin of Moon.

Simulation of how Theia (black), orbiting in Langrange point L4 before it collided head-on with Earth (blue) before the remnants condensed into Moon (gray) SOURCE

Theia, a hypothesized planetary-mass planet was said to be the size of Mars. In the early Solar System, Theia was an asteroid, also called Earth trojan, orbiting in Langrange points L4 and L5. Based on the investigation, astronomers think that the collision happened before our Solar System was formed, approximately 100 million years before. It was said that Theia had struck a nearly full formed Earth at a 45 degrees angle with a strapping side swipe, with an impactor velocity of 4m/s which is quite relatively slow. There is also a hypothesis which says that the impact initiated a vigorous mixing which made Theia’s iron core to mix into Earth’s core and Theia’s mantle assembled into Earth’s.

Due to the impact, shock wave spread out and materials from both planets were jumbled together and discharged out into the orbit. The materials, consisting of rocks and minerals orbit around the Earth for some time before they fused together, forming the Moon we know today.

The artist’s depiction of the collision. SOURCE

One of the evidences which support this event was the similarities in the oxygen isotopes of both Earth and Moon. Edward Young, a geochemistry professor at UCLA and also the one who lead the study, found that the oxygen isotopes that were found on Earth and Moon are indistinguishable. This furthermore support the argument that Theia had thoroughy mixed into Earth before their debris coalesced to form Moon. Further read can be done here.

More investigations are still being made, and many hypothesis are still being voiced out by astronomers. The verdict? I myself am still not sure. Whatever it is, I believe that everything has their own existence.







The idea of discovering new “Earth-like” planets has always intrigue me! I mean, they could be habitable planets that we can ACTUALLY live in? Just like in Terra Nova (I’ll explain more about that series in the end of this post!). Super-Earth, in short, means exoplanets in which their masses are higher than Earth’s, extra points if they are in habitable zones! For now, I am just going to focus on one habitable zone which is Kepler-62. Before that, hats off to those who guess why the zone’s name is Kepler! KEPLER is the name of NASA’s spacecraft in which its job is to find Earth-size planets orbiting another star AND it is also named after Johannes Kepler, world’s renowned astronomer.

The illustration shows Kepler-62f (in front) and Kepler-62e (the twinkle on the right) orbiting Kepler-62 star. SOURCE

Kepler-62 is the name of a star in Lyra constellation (somewhat cooler than our Sun). It is the smallest habitable zone found and hosted about five exoplanets. There are two main planets in Kepler-62 zone which are Kepler-62e and Kepler-62f.

Most likely to be a water world, Kepler-62e is an exoplanet with 1.6 times the size of Earth. It orbits the red dwarf star once every 122 days. The planet is roughly 1200 light years from Earth and is believed to be more gaseous than rocky, thus called mini-Neptune. Another exoplanet orbiting the same Kepler-62 is called Kepler-62f. This planet is a bit farther out compared to Kepler-62e, seeing as its orbital period is 267 days. It is 1.4 times bigger than Earth and its equilibrium temperature is close to Mars’. Through estimation of its mass, Kepler-62f is most likely to be a rocky planet.

The Kepler-62 system with its habitable zone in compared to our Solar System. Only two planets are in the zone which are Kepler-62e and Kepler-62f. SOURCE

After further research, it was found that both of the planets are similar to Earth but slightly bigger. It was also discovered that both planets are likely dominated with ocean. Any chances that there are life on those planets? Follow-ups exploration and research are being done to find out more about the habitable zones and other exoplanets. Are there any more habitable zones out there? YES. In fact, there was another zone found in 2013 and was named Kepler-69 and there are actually many more out there!

Now, there is one TV show that I would recommend you guys to watch. Titled Terra Nova, it tells us about the life of a family in far future, where Earth is no longer fit for living due to overpopulation and declining air quality. So, they have to move to another world called Terra Nova where in that world, it was as if Earth was pulled back to the past (means dinosaur still exist!) and they have to fight to survive. Quite a good series, seeing that I am into science fiction. Give it a chance, if you have some time! (It’s on Netflix, btw)