The Chinese Tiangong space station and the International Space Station (ISS) can both be seen in the sky over North America on July 5th!
This does not happen often, because their orbits are different and their inclination angles are also different.
On July 4th, the U.S. "Space News" published an article by scientists.
From July 3rd to July 8th, it will be possible to see the two largest objects currently orbiting the Earth, which will pass one after another in the pre-dawn sky within a few minutes.
During the upcoming week, amateur astronomers in the southern parts of the United States and Canada will have the opportunity to watch the two largest spacecraft currently orbiting the Earth in the sky for a few minutes.
They are the International Space Station (ISS) and China's space station Tiangong. Figure 1
If you get up a few hours before dawn, you may see both within half an hour.
It is possible to see both in the sky on the morning of July 5th.
The International Space Station is the largest and brightest artificial object orbiting the Earth.
In its most favorable passage, it can be 2.5 times brighter than Venus, and nearly 40 times brighter than Sirius, the brightest star in the night sky.
China's space station Tiangong is smaller than the International Space Station, with an overall size about one-fifth that of the ISS.
Like the International Space Station, it is a significant target when moving through the night sky. During its most favorable passage, its brightness can reach the level of Venus.
From now until the end of July, people in North America and Europe will have many opportunities to see the International Space Station (ISS) and Tiangong passing overhead, mainly due to seasonal factors.
Nighttime is now the shortest, and low-Earth-orbit (LEO) satellites like the ISS and Tiangong can be bathed in sunlight all night long, something that is not achievable at other times of the year.
Because these two space stations orbit the Earth approximately every 90 minutes, it is possible to see them pass over multiple times consecutively.
On the morning of July 5, 2025, the International Space Station and China's Tiangong space station are expected to appear simultaneously in the observation range of amateur astronomers in eastern North America and the Atlantic coast.
About between 3:56 AM and 3:58 AM Eastern Daylight Time, the International Space Station will pass over New York in the north, while the Tiangong space station will pass over New York in the south. Figure 2
This does not happen often because their orbital altitudes are slightly different, and the orbital inclination angles of the two space stations are also different: the orbital inclination angle of the ISS is 51.63 degrees, while the orbital inclination angle of Tiangong is 41.46 degrees.
Original text: https://www.toutiao.com/article/1836667285416960/
Statement: The article represents the views of the author.