The Sun will consume the Earth and collapse to the size of the same:
When Sun runs out of Hydrogen it burns Helium and expands to the point that it will engulf Mercury and Venus and possibly Earth. At this stage it will become a red giant. Later it will collapse down to the volume of our planet. When this happens, it will be called a white dwarf.
The Moon is drifting away from the Earth:
The Moon is moving ~3.8 cm away from our planet every year and estimated to do so for next 50 billion years. By the time, our sun will be dead already and RIP as White Dwarf, the Moon will be taking around 47 days to orbit the Earth instead of the current 27.3 days if both survive.
The Moon has no atmosphere:
This means that the surface of the Moon is constantly bombarded with cosmic rays, meteorites and solar winds, and has huge temperature variations. No sound can be heard on the Moon, and the sky always appears black. A pretty good destination for star gazing isn’t it?
Side effects of solar eclipse:
During a total solar eclipse, conditions in the path of totality can change quickly. Air temperatures drop and the immediate area becomes dark. If any planets are in the sky at the time of a total solar eclipse, they can be seen as points of light.
The gassy but massive Sun:
The Sun’s mass is 1,989,100,000,000,000,000,000 billion kg or 333,060 Earths. This is 99.86% of the total mass of our Solar System, about three quarters of this mass is hydrogen and the rest is mostly helium.
Center of our galaxy is a black hole:
The Milky Way’s central core contains a super-massive black hole. It is commonly referred to as Sagittarius A*. It contains the mass of about 2.6 million Suns.
We are on a collision course with our neighbor:
Our galaxy will collide with our neighbor Andromeda Galaxy(M31) in about 5 billion years. Any how, the stars involved are sufficiently far apart that it is improbable that any of them will individually collide. The galaxy that will be the result of the collision is nicknamed Milkomeda.
Shooting stars are not stars:
Comets are pieces of solar system ices traveling in orbit around the Sun. As a comet gets closer to the Sun, its ice sublimates and streams out to populates the comet’s orbit. If Earth happens to move through that stream, those particles fall to Earth as meteor showers(shooting stars).
Pluto was reclassified from a planet to a dwarf planet in 2006:
This is when the IAU(International Astronomical Union) formalized the definition of a planet as “A planet is a celestial body that, (A) Is in orbit around the Sun, (B) Has sufficient mass for its self-gravity to overcome rigid body forces to become nearly round shape, and (C) Has cleared the neighborhood around its orbit.” Sadly, Pluto doesn’t satisfy the 3rd property.
Hottest planet is not the closest planet to the Sun:
Despite being closest to the Sun, Mercury is not hottest. The surface of Mercury which faces the Sun sees temperatures of up to 427°C, whilst on the alternate side this can be as low as -173°C. This is due to the planet’s slow rotation and having no atmosphere to help regulate the temperature. Venus experiences highest temperature of 465°C due to its active volcanism and CO2(Greenhouse gas).
Mars is home for largest mountain & dust storms in the solar system:
Approx 2.5 times higher than Mt Everest. Olympus Mons(volcano) on Mars is 21km high and 600 km in diameter. Despite having formed over billions of years, many scientists believe it could still be active. The dust storms on Mars can last for months and cover the entire planet. The seasons are extreme because of its tilt combined with second most elliptical orbit around the Sun after Mercury. If you watched ‘The Martian’ you would know how fierce they can become!
Halley’s comet won’t be visible till 2061:
Discovered in 1705 by Edmond Halley, the famous comet was last seen in 1986 and is only seen once every 75 to 76 years. Making it once in a lifetime celestial event.
A year on Earth isn’t 365 days:
It’s actually 365.2564 days. It’s this extra 0.2564 days(6.1536 Hrs) that creates the need for leap years by adding an extra day(leap day) in February. Even adding of an extra day every 4 yrs will end up with 3 extra days every 4 centuries so we exclude the centuries which are not divisible by 400 (For example, 1700, 1800, and 1900 were not leap years, but 1600 and 2000, which are divisible by 400 were.). So the next century leap year is 2400.
Lightning on Earth and beyond:
It is estimated that lightning is five times hotter than the Sun and hits Earth 100 times/sec. That’s 8.6 million strikes/day. It also has been confirmed through direct observation on Jupiter, Saturn, and Venus. Other planets are rumored to have lightning, such as Uranus and Neptune, however it hasn’t been confirmed by observation yet.
The largest planet with the shortest day:
Jupiter is 2.5 times massive than all the other planets in the solar system combined and turns on its axis, once in mere 10hrs. The rapid rotation is a cause of huge storm on Jupiter(The Great Red Spot) raging for at least 350 years. It is so large that three Earths could fit inside it.
Saturn can float on water:
Saturn the gas giant, is the only planet in solar system which is less denser than water. Which would float if we place it in a really.. really… big tub full of water!
Why 7 days a week:
Based on 7 moving objects in the night & daytime sky, the Sun, Moon and the 5 naked eye visible planets(Mercury,Venus,Mars,Jupiter & Saturn), giving us Sun for Sunday, Moon for Monday, Tiw for Tuesday, Woden for Wednesday, Thor for Thursday, Fria for Friday and Saturn for Saturday as per Teutonic(ancient European language) names. And you can find the similar mnemonics in Indian calendar weeks too.
The space suits-costliest and heaviest:
While the entire suit costs a whopping $12million, 70% of that cost is for the backpack and control module. They weigh ~82 kg on Earth. If it weren’t for a lack of gravity in space, the suit would be too heavy to use.
Like a diamond in the sky:
Yale University scientists suggests that a rocky planet called “55 Cancri e” with the planet-hosting star 55 Cancri located at 40 light years away, but visible to the naked eye in the constellation of Cancer, which has a radius twice Earth’s, and a mass eight times greater, may have a surface made up of graphite and diamond.
That’s one small step but not short step for mankind:
The Moon has no atmosphere, which means there is no wind to erode the surface and no water to wash the footprints away. This means the footprints of the Apollo astronauts, along with spacecraft prints, rover prints and discarded material, will be there for millions of years.
Where day is longer than a year:
Venus has a slow axis rotation which takes 243 Earth days to complete its day. The orbit of Venus around the Sun is 225 Earth days, making a year on Venus 18 days less than a day on Venus.
The Earth is on a diet:
It’s losing 50k tonnes of mass every single year, even though an extra 40k tonnes of space dust converge onto the Earth, it’s still losing weight.The biggest mass loss comes from escaped ‘H’ & ‘He’. These elements are too light to stay permanently in the gravity, so they tend to escape into space.The net loss is about 0.000000000000001% mass of the Earth every year. So, It will take trillions of years for all of the H & He to be depleted.
Space is not too far:
Space officially begins at the universal marker of the Karman Line. This invisible boundary is 100 km above the Earth. In theory if you could drive your car upwards, you could be in space in less than hour.
The moon looks bigger on the horizon:
It is an optical illusion which makes the moon appear to be larger the lower it is in the sky. The apparent magnification is not caused by our atmosphere. It is more of a mind trick. When the moon is closer to the horizon, it is closer to objects like buildings and trees which therefore in comparison makes the moon look bigger.
You can cry in space but your tears don’t fall:
On-board the ISS, water floats like bubbles or spheres. However the water will hold onto a surface until it is knocked out. This means that tears start to form bubbles around your eyes as the weightless environment is not causing your tears to fall.
Nebulae-Hidden beauty of the universe:
Nebulae come in all shapes and sizes, made of clouds of interstellar dust and gases, where stars born and die. There is a Christmas tree nebula, a cat’s eye, a horse-head, a unicorn, a hand, fried egg and lots more. These beautiful clouds which are not visible to the naked eye really highlight the fact there is a lot more happening in the night sky than what we can see.