The asteroid Florence will pass safely by Earth on September 1, 2017, at a distance of about 6.7 million kilometers , the equivalent of 18 times the distance from Earth to the Moon. Florence is among the closest asteroids to Earth that are several kilometers in diameter. Measurements from NASA’s Spitzer Space Telescope and NEOWISE mission indicate it is about 4.4 kilometers in diameter.
Recall that the asteroid that started the mass extinction that wiped out the dinosaurs was about 10 kilometers in diameter.
“Although many known asteroids have passed closer to Earth than Florence will on September 1, they were all smaller,” said Paul Chodas, director of NASA’s Center for Near Object Studies (CNEOS). ” Florence is the largest asteroid to pass this close to our planet since NASA’s program to detect and track near-Earth asteroids began.”
This relatively close encounter provides an opportunity for scientists to study the asteroid closely. The radar images obtained will show the actual size of Florence and could also reveal details of its surface.
Radar has been used to observe hundreds of asteroids. When these small ‘birth certificates’ of the formation of the solar system pass relatively close to Earth, deep space radar is a powerful technique for studying their sizes, shapes, rotation, surface features and roughness , and for a more precise determination of its orbital path.
Can it be seen from Earth?
The answer is yes, although only fairly expert observers will be able to see it.
Florence is the brightest of the known large asteroids, so it can become visible the moment it is closest to Earth. In order to appreciate it, it will be necessary to look in the right direction: Florence will progressively go through the constellations of Pisces Australis, Capricorn, Aquarius and Delphinus. In addition, you will have to wait between five and ten minutes to see a slight displacement of a point in the sky , which will be the almost imperceptible movement of Florence.
It works against, in addition to the almost 7 million kilometers of distance, the fact that Florence does not move too fast: it barely moves about 14 kilometers per second while the Earth moves at almost 30 kilometers per second.
The asteroid Florence was discovered in March 1981 . It was named after Florence Nightingale (1820-1910), the founder of modern nursing.
The 2017 encounter is the closest this asteroid has been to Earth since 1890. The last time we crossed paths was on August 29, 1930, and we won’t meet again until September 1, 2057. NASA scientists They estimate that for about 500 years it will not be as close to Earth as it is now.
Images: NASA
