[ad_1]
For the second time this year, the five brightest planets can be seen simultaneously. You can catch them looking towards the western sky after sunset. The planets will form a line emerging from the horizon.
Mercury and Venus are low in the west, with brilliant Jupiter shining just above. Saturn is higher in the northwest sky, and the red planet Mars flies over the series of five.
On Friday, October 12, a beautiful crescent moon is just to the right of Jupiter. Keep watching the planets night after night and you can follow the progress of the Moon. As the Moon travels the Earth each month, its apparent movement in the sky is much faster than the quieter movement of the planets in their orbit around the Sun.
On Monday, October 15, the Moon will rise higher in the sky to sit near Saturn, and a few days later, on October 18, the Moon will partner with Mars.
It will also be a perfect evening to see the planets, because Venus and Mercury will sit side by side. Of the five planets, Mercury is the weakest and therefore the most difficult to see. Having brilliant Venus as an indicator of Mercury is always an advantage.
In about a week, Venus, who has been the brilliant evening star for most of the year, will pass by the light of the sun and move away from the night sky.
Five planets, two groups
The planets have been dancing happily in the night sky over the last few months.
Back in July, they also met in the evening sky, but on that occasion, they were laid in the sky. Mercury and Venus were in the west, while Jupiter, Saturn and Mars were rising to the east.
As Mercury and Venus are the inner planets, gravitating around the Sun in the same way as the Earth, we only see them very low in the west after sunset, or in the east before sunrise of the sun. These are the planets that follow or lead the Sun.
On the other hand, the outer planets of Mars, Jupiter and Saturn can drift into the sky, which they have been doing since July. The trio moved from east to west and now they join Mercury and Venus to mount the show of the five planets.
There is more in store
This may seem like a common phenomenon, since the five planets have come together in the space of only a few months. But this is possible only because Jupiter and Saturn are currently on the same side of the Sun and are therefore relatively close to each other.
The five planets have met twice this year and twice in 2016, but before that, a decade ago, it was just not possible. The two gas giants were too far away from each other.
As Jupiter and Saturn meet in the sky, it is only a matter of time before the other planets fall into the right configuration to bring them together.
Next time it will be in July 2020, but it will be more difficult to see this week. The planets will be extended in the sky rather than being all clustered in the west as they are now. It is therefore always special to spot the meeting of the five planets. It is a great satisfaction to be able to check the five planets in one visualization.
Want a challenge?
Not only are the five easy-to-see planets visible in the evening sky, but they are also joined by Uranus and Neptune to complete the planetary whole.
These two ice giants that revolve around Saturn are modern planets. They were not known in antiquity because their discovery required the help of a telescope and the understanding of gravity to understand how the solar system works.
But although they are not visible to the naked eye, Uranus is low in the east at sunset and Neptune is higher, about halfway to Mars.
Experienced observers, observing the sky from a dark country site, could see Uranus at the naked eye knowing exactly where to look. Through binoculars, Uranus appears as a weak star, but a good telescope will show its slightly bluish disc.
It is best to wait until later in the evening, when Uranus will climb higher, to try to observe it. But this is the ideal moment, because the planet is getting closer to the opposition on October 24, when it will be at its best.
Neptune is about the same size as Uranus but is much farther away, which makes it harder to see. Even with a modest telescope, it appears as a bluish star, while adequate viewing conditions and a high-quality telescope are needed to reveal the Neptune disk.
Finally, and not to be outdone, even the Pluto dwarf planet joins the crowd. It is far too small and remote to be seen, but is currently halfway between Saturn and Mars.
Even with a high quality telescope, Pluto never appears as a star-like object, and for most people it will be difficult to find it in its current position among all the stars near the bright Milky Way .
If you're up for the challenge, a free astronomy program like Stellarium is great for helping you locate planets. But it is equally gratifying to take advantage of the five luminous planets, observed since ancient times, which meet briefly in the western sky.
Tanya Hill is an honorary member of the University of Melbourne and Senior Curator (Astronomy) at Museums Victoria, Australia.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
[ad_2]
Source link
