Author: Fraser Cain

The confirmed coldest temperature on Earth was recorded in Vostok, Antarctica at a brisk -89.2 degrees Celsius (183 Kelvin). There is an unconfirmed report of the temperature reaching -91 degrees Celsius (181 Kelvin); either way you look at it; you are still freezing your butt off.

The high velocity winds at the South Pole don’t make enduring the cold any easier by the dedicated scientists that work there. Winds can reach a velocity of 90 m/s. These temperatures were recorded during the Antarctic winter in June and July, during the period when the sun never actually rises. Even at its balmiest, Vostok only reaches temperatures of around -25 degrees Celsius (248 Kelvin). When we are looking at temperatures that cold, the Kelvin scale helps make the picture look less bleak; no ominous negative sign out front to make you lose all hope of getting warm. Incidentally, the warmest recorded temperature at Vostok was -19 degrees Celsius (254 Kelvin).

Vostok’s elevation is almost 3500 meters above sea level, and due to the density of oxygen being less towards the poles, the scientists are working at an effective height of 5000 meters above sea level.

Why would we journey to such an inviting place you might wonder? Vostok is located 1300 kilometers from the true South Pole, but is very near the Magnetic South Pole. Scientists study actinometry; the measure of solar radiation in photons, geophysics; the study of the physical properties of the Earth, mainly electrical, gravitational and magnetic forces which also includes seismology, and climatology; the study of weather systems.

Humanity may end in many different ways. We might kill ourselves through nuclear war, or die from a global disease epidemic. Like all the species on Earth, we’ll eventually be gone. But life will survive and continue to evolve into new and interesting forms. But even the Earth won’t last forever. Eventually, our planet too will end.

So, how will the Earth end? It all depends on how the Sun ends.

The Sun is a happy main sequence star right now, but as it nears the end of its life in about 7.5 billion years, it will begin to swell up as a red giant star. Its size will get so large that it will encompass the orbits of the inner planets. Mercury and Venus will be consumed within the Sun.

As the Sun grows, it will let off ferocious solar winds that dwarf its current winds. These winds will cause the Sun to lose a tremendous amount of mass, and this mass loss will cause the orbit of the planets to start spiraling outward. Scientists used to think that this spiraling outward might actually save Earth. Instead of being consumed by the Sun, it would keep spiraling, always keeping one step away from the expanding Sun.

The current thinking is that it’s not going to be fast enough. Although Earth’s orbit will be spiraling outward, it won’t be fast enough to keep pace with the expansion of the Sun as it becomes a red giant. At some point, roughly 7.5 billion years from now, Earth will end; it’ll be gobbled up just like Mercury and Venus before it.

By that time, let’s hope that future humans have relocated to the outer Solar System. By that time, the habitability zone around the Sun will have expanded to the point that water can be a liquid around Kuiper belt objects, like the dwarf planet Pluto. Can you imagine sitting on a beach on Pluto?

You can read more about the end of the Earth in this article. And you can read about the end of the entire Universe in this article.

If you’re talking about majestic ice rings, like we see around Saturn, Uranus or Jupiter, then no, Earth doesn’t have rings, and probably never did. If there was any ring of dust orbiting the planet, we’d see it.

It’s possible that there were rings orbiting Earth in the past. Some scientists think that Earth’s gravity could have broken up a comet or asteroid that got too close to the planet, but didn’t actually collide. This is similar to what happened to Comet Shoemaker/Levy 9 that eventually crashed into Jupiter. First the giant planet tore the comet up, and then the pieces crashed into the planet on a later orbit.

In the case of Earth, it might have held onto a few ice particles that would have then orbited the planet, and eventually crashed through our atmosphere and burned up. Even the smallest particles of ice or dust create spectacular meteors in the sky, so there was a ring right now, we’d see these impacts all the time.

Other scientists think that a giant asteroid impact with Earth, such as the one the killed the dinosaurs 65 million years ago, might have kicked up a huge ring of debris around the planet. This ring would cast a shadow down on the surface of the Earth, changing the planet’s climate, and could last for a few million years at most.

Finally, humans have put up an artificial ring in the past. The US Military launched 480 million copper needles into orbit around Earth in a project called Project West Ford. Scientists could bounce radio signals off the needles and communicate between two locations on Earth. This worked for a few months after launch, until the needles were too far dispersed to allow for communication. In theory, if needles were continuously launched, it would be a functioning communications system, but it’s not necessary with modern communications satellites.

So Earth probably did have temporary rings in the past after asteroid impacts or cometary flybys, but Earth doesn’t have rings today.

The Earth has a mass of 5.97×10²⁴ kg.

You can also check out these books about the planet Earth from Amazon.com for more detailed information.

If you could actually break up the planet into its various parts, you’d get 32% iron, 30% oxygen, 15% silicon, 14% magnesium, and then all the other elements, with sulfur, nickel, calcium and aluminum being the most common.

The density of Earth is 5.5 g/cm³. This is actually the densest planet in the Solar System; however, this is partly because of the size of Earth. The next most dense planet is Mercury, and it would actually be more dense than Earth if it wasn’t so small. Earth pulls at itself with so much gravity, that it compacts down tighter than Mercury.

How did scientists find out the mass of Earth? By studying how things fall towards it. Gravity is created from mass. The more mass an object has, the more gravity it will pull with. If you can calculate how an object is being accelerated by the gravity of an object, like Earth, you can determine its mass.

In fact, astronomers didn’t accurately know the mass of Mercury or Venus until they finally put spacecraft into orbit around them. They had rough estimates, but once there were orbiting spacecraft, they could make the final mass calculations. We know the mass of Pluto because we can calculate the orbit of its moon Charon.

When you choose a telescope, there are two main kinds you can pick from, reflectors and refractors. Both can be wonderful for viewing the night sky. They use basically different methods to boost light from dim objects in the sky. Here’s how they work, and how they’re different.

Refractor Telescopes
Here’s what’s inside a basic refractor telescope. The job of the objective lens, opposite the eyepiece end, is to gather the light coming from a distant object, such as a star, and bend it into a single point of focus. A second lens’ (the eyepiece) job is to enlarge that focused image for our retina; it acts as a magnifying glass. Think of the focused light coming in from the first lens as a bug, and think of the eyepiece magnifier as a basic magnifying glass that we look at the bug with. That’s it in a nutshell.

Reflector Telescopes
A reflector telescope uses two mirrors instead of two lenses. Isaac Newton developed this telescope to combat chromatic aberration (a rainbow seen around some objects viewed with a refractor telescope). A mirror used to gather light doesn’t suffer from this effect. Light from an object enters the telescope tube and is reflected off a curved mirror at the end of the tube. A second, small, flat mirror in the middle of the tube reflects this image to the eyepiece. There are potential problems associated with the mirrors. Firstly, some light is always lost in the reflection; good quality telescopes can usually gather 90% of the light coming in. Secondly, the mirror might not be a perfect curve, so the image being reflected will not come to a perfect point. This results in a dragging effect; a point could be seen as a line or cross. Also, the mirrors need to be cleaned and realigned from time to time.