A hemisphere’s winter solstice is the shortest day of the year and its summer solstice the year’s longest. (In the Southern Hemisphere the seasons are reversed.) The equinoxes happen in March (about March 21) and September (about September 23).

The equinoxes and solstices are caused by Earth’s tilt on its axis and ceaseless motion in orbit. You can think of an equinox as happening on the imaginary dome of our sky, or as an event that happens in Earth’s orbit around the sun.

The winter solstice is the day when the Northern Hemisphere is tilted farthest away from the Sun and begins to move towards it again. In the Northern Hemisphere, the winter solstice is on December 22nd. This will be the shortest day of the year, and thus have the longest night.

One side of the Earth faces the sun, while the other side faces away into space. The side facing the sun is bathed in light and heat—we call this daytime. The side facing away is cooler and darker, and experiences night.

It is all about the tilt of the Earth’s axis. Many people believe that the temperature changes because the Earth is closer to the sun in summer and farther from the sun in winter. In fact, the Earth is farthest from the sun in July and is closest to the sun in January!

Our sun’s death is a long way off — about 4.5 billion years, give or take — but someday it’s going to happen, and what then for our solar system? The trouble begins before the death proper: The first thing we have to contend with is the elderly sun itself.

We are not getting closer to the sun, but scientists have shown that the distance between the sun and the Earth is changing. The sun’s weaker gravity as it loses mass causes the Earth to slowly move away from it. The movement away from the sun is microscopic (about 15 cm each year).

In our Solar System, we have many objects that orbit the Sun or other bodies. According to the latest research, there’s approximately a 1% chance that one or more of the four inner planets in our Solar System today — Mercury, Venus, Earth and Mars — will become orbitally unstable over the next few billion years.

Spaceweather.com reports that already there have been 100 days in 2020 when our Sun has displayed zero sunspots. That makes 2020 the second consecutive year of a record-setting low number of sunspots— which you can see (a complete absence of) here.

A lack of gravity would eventually take its toll on our very planet, writes Masters. “Earth itself would most likely break apart into chunks and float off into space.” Without the force of gravity to hold it together, the intense pressures at its core would cause it to burst open in a titanic explosion.

When gravity disappears for 1 second the outwards force balanced by the gravity would be released causing a massive explosion. In other star systems with more immense stars and natural phenomena such as pulsars and and especially black holes the explosions and expansions would be greater.

If the Earth stopped spinning suddenly, most people on Earth would die. If the Earth slowed down gradually, it would be absolutely devastating, but there is a chance some people could survive.

The moon influences life as we know it on Earth. It influences our oceans, weather, and the hours in our days. Without the moon, tides would fall, nights would be darker, seasons would change, and the length of our days would alter.

We would lose all tides on the Earth, as these are governed by the gravitational force of the Moon. The sun weighs 100,000,000 times more than the moon. So it would be a bit like a fly crashing in to a 300 ton ship. The ship wouldn’t notice it at all.

NASA cameras have captured video of the largest explosion it has ever seen on the moon… ‘For about one second, the impact site was glowing like a fourth magnitude star,’ NASA said. The meteoroid was traveling around 56,000 miles per hour when it slammed into the moon’s surface.

No asteroids have ever been observed to hit the Sun, but that doesn’t mean that they don’t! Asteroids are normally content to stay in the asteroid belt between Mars and Jupiter, but occasionally something nudges them out of their original orbits, and they come careening into the inner solar system.

No. Asteroids ORBIT the sun. A thing cannot POSSIBLY crash into something that it ORBITS unless something happens that causes the orbit to loose ALL of its energy (ie, velocity). They can hit earth (and other objects) because our orbits can CROSS (intersect).

If a comet is big enough and passes close enough, the steep fall into the sun’s gravity would accelerate it to more than 600 kilometres per second. The momentum propelled by the comet could even make the sun ring like a bell with subsequent sun-quakes echoing through the solar atmosphere.

The Chicxulub impactor had an estimated diameter of 11–81 kilometers (6.8–50.3 mi), and delivered an estimated energy of 21–921 billion Hiroshima A-bombs (between 1.3×1024 and 5.8×1025 joules, or 1.3–58 yottajoules).

Asteroids with a 1 km (0.62 mi) diameter strike Earth every 500,000 years on average. Large collisions – with 5 km (3 mi) objects – happen approximately once every twenty million years.

Don’t worry: Despite its proximity to Earth, the black hole is no danger to us. Astronomers estimate there are hundreds of millions of black holes in our galaxy. The latest discovery gives them hope that there are others lurking around nearby stars, perhaps even some of the most familiar points of light in our sky.

By that point, all life on the Earth will be extinct. The most probable fate of the planet is absorption by the Sun in about 7.5 billion years, after the star has entered the red giant phase and expanded beyond the planet’s current orbit.

25 million meteoroids

The Sylacauga meteorite fell on November 30, 1954, at 12:46 local time (18:46 UT) in Oak Grove, Alabama, near Sylacauga. It is commonly called the Hodges meteorite because a fragment of it struck Ann Elizabeth Fowler Hodges (1920–1972).