Mars, which became brightest in two years and two months, has led many people to look up at the night sky. Mars is brightest because the distance between Earth and Mars is getting closer. The Earth, which was closest to Mars on the 6th, passed exactly between the Sun and Mars on the morning of the 14th, and is now gradually moving away from Mars behind it. But by the end of this month, you can see Mars shining brighter than Jupiter in the evening sky.
The protagonist of this week’s constellation tour is Cassiopeia, an important guide to the northern sky along with the Big Dipper. The W-shaped constellation Cassiopeia becomes an important milestone in the northern sky in autumn when the Big Dipper descends near the horizon and is hard to see.
Orion meteor shower maximal
One of the coolest scenes you can see in the night sky is a shooting star breaking through the sky. Shooting stars, which are usually difficult to see one or two per hour, sometimes look like a bunch, and this phenomenon is called a meteor shower.
Meteor showers appear when the Earth passes through the orbit of the comet. A meteor shower is a phenomenon in which debris from a comet’s tail is sucked into the atmosphere due to the Earth’s gravity and collides with the air and burns. This week is the time when the meteor shower in the constellation Orion falls the most. The meteor shower in the constellation Orion is named because the Earth meets the orbit of a comet in the direction of the constellation Orion. The point where Earth meets the orbit of a comet is called the radiation point of a meteor shower.
Meteor showers in the constellation Orion appear for about a month from early October to early November every year, and up to 20 to 30 shooting stars are expected to fall at dawn on October 21st or 22nd.
Comet Halley in 1986 Ⓒ NASA
The meteor shower in the constellation Orion is a shooting star created by debris from Comet Halley. The Earth meets the orbit of Comet Halley, which has a period of 76 years, twice a year, such as the Eta Aquarius meteor shower in May and the Orion meteor shower in October. Although it does not belong to the three major meteor showers (Quarter meteor shower in January, Perseus meteor shower in August, Gemini meteor shower in December), the meteor shower that sprinkles the most shooting stars per hour. Are these meteor showers.
The falling speed of a shooting star is usually about 20 to 70 km per second, but the shooting stars in the Orion meteor shower are known to move very fast at 60 to 70 km per second. Due to its high speed, it sometimes leaves traces of shooting stars along the trajectory that has passed, and sometimes causes small explosions. However, most of comet debris are small in size and consist of flammable components in the atmosphere, so they do not actually fall to the ground and leave a meteorite. Most of the bright shooting stars that leave meteorites are stones or iron debris from asteroids.
The radiation point of the meteor shower in Orion is the boundary from Orion to Gemini. The constellation Orion rises in the eastern sky late at night and rises highest in the southern sky around 4-5 o’clock before sunrise. Therefore, it is not necessary to stay up all night from early evening to see the meteor shower in Orion. If you think of the earth as a running bus, the part that corresponds to the windshield is the dawn side, so the most frequent meteor shower is around dawn. In particular, there is no moon at dawn on the 21st and 22nd, so if the weather is clear, you will be able to see more shooting stars.
Radiation Point of Meteor Shower Orion Ⓒ The Association of Lunar and Planetary Observers (ALPO)
Guide constellation in the northern sky in autumn ‘Cassiopeia‘
North sky at night on October 19th. Ⓒ Stellarium, Astronomical Space Project
One of the easiest constellations to find in autumn is the W-shaped constellation Cassiopeia in the northern sky. The constellation Cassiopeia, which can be seen on the opposite side of the Big Dipper from Polaris, can be found high in the northern sky on the autumn evening when the Big Dipper descends near the horizon. The constellation Cassiopeia can be found in a cluster of tiny stars, because it is located at the corner of the Milky Way.
Cassiopeia photo taken with a smartphone. Ⓒ Taehyung Lee
According to Greek mythology, Cassiopeia was the queen of Ethiopia, a very vanity woman. She boasted that her daughter, Princess Andromeda, was more beautiful than the sea fairies, and she suffered the bad luck of offering her daughter for wealth to the monster whale sent by Poseidon, the god of the sea. However, it turned into a phone call and took the hero Perseus as son-in-law, and both he and his family were honored to become a constellation in the sky. Of course, Cassiopeia himself is said to have been hanging upside down while sitting on a chair for half a day as punishment for vanity.
Cassiopeia is one of the most famous constellations, but it is also the most difficult to imagine. It would be better to think of it as a mountain with two peaks or a camel with two humps on its back.
This constellation can be used as a guide for finding the North Star when the Big Dipper is difficult to see. By connecting the two stars of the W-shape inward and connecting the point where they meet and the second star in the middle, you can find a polar star of similar brightness by going five times.
How to find Polaris using Cassiopeia. Ⓒ Astronomical Space Planning
Jupiter and Saturn, And the moon
Mars is the brightest star in the evening sky, but Jupiter and Saturn are also the prettiest stars in the telescope. Of course, the biggest and most colorful thing is the moon. Although Jupiter and Saturn, which handed over the throne of the evening sky to Mars during the month of October, it is expected to show a wonderful scene with the moon this week.
Southern sky at night on October 22nd and 23rd. Ⓒ Stellarium, Astronomical Space Project
On the evening of Thursday (22nd), Jupiter can be seen just above the moon, and on the evening of Friday (23rd), the moon can be seen just behind Jupiter and Saturn. The moon and the two planets are already set in the western sky around 10 o’clock, so the time to see a wonderful scene is about 2-3 hours.
The moon passing by the planet occurs once a month. This is because the way the moon passes in the sky and the way planets pass are almost the same. The planets of the solar system orbit the sun in orbits similar to the ecliptic, the orbit of the Earth due to the sun’s strong gravity. The angle between the orbits of planets and the ecliptic is called the inclination of the ecliptic, and Jupiter, Saturn, and Mars are all about 2 degrees. Baekdo, the orbit of the moon in the sky, is only about 5 degrees apart from the ecliptic at its maximum distance, so the moon passes by each planet once a month.