Get Ready for Asteroid Flora This Halloween

Asteroid Flora will be at its brightest for thirteen years around Halloween this year. Reaching magnitude 8, it will remain below the limit of the naked eye visibility, but can be easily seen with binoculars.

Asteroid Flora was discovered in 1847 by John Russel Hind (1823-1895) from the George Bishop’s privately owned observatory in London. It was the eighth asteroid to be discovered and was named after the Roman goddess of flowering plants.

Observing Flora this year will be special because of a favourable coincidence. First, it will be at opposition to the Sun. This means that Earth will be directly between the Sun and Flora, and that Flora will be at its closest to the Earth, making it appear brighter. Oppositions between Earth and Flora happen roughly every 1 year and 5 months. 

The coincidence is that during this year’s opposition, Flora also happens to be at its closest to the Sun and so its brightness will be increased even more. This is because Flora follows an elliptical orbit and this year’s opposition corresponds to the asteroid reaching its closest approach to the Sun, thus bringing it even closer to Earth.

Orbits of the asteroid Flora with the inner planets of the Solar System and their positions on November 1, 2020. Note the alignment between the Sun, the Earth and the asteroid. (Astro Van Buitenen)

This coincidence is called a perihelic opposition and occurs once every 13 years. The last time it happened was in November 2007 and the next will be in November 2033. This year, the nights of 31 October and 1 November will be the best for viewing because the asteroid will be 131 million km from Earth.

Flora will be in the constellation Cetus, the Whale. Although faint, Cetus is relatively easy to locate due to its large and close proximity to the zodiacal constellations of Aries, the Ram; and Taurus, the Bull.

Trajectory of the asteroid Flora in the constellation Cetus, the Whale in the last months of 2020 (In-the-sky.org)

Although the pandemic means that organising observing events may be difficult depending on the restrictions where you live, there is still opportunity to produce great content. The asteroid’s name is rich in mythology, the biography of the discovering astronomer, or curiosities about the location where the asteroid was discovered are all things to explore. 

There is not much known about this asteroid but a 3D image of it based on previous observations is an interesting tool to explore. Measurements suggest that Flora is elongated with dimensions of approximately 140x140x115 km.

See exactly where Flora is at any moment, visit The Sky Live. Enjoy this moment because your next chance will be 13 years from now!

Clear skies and good events!
Saulo

ABOUT THE AUTHOR: 

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Saulo Machado is the Asteroid Day Global Event Coordinator. Since 2016, Saulo has been the Brazil Regional Coordinator, where he helped organizers host their Asteroid Day events all over Brazil.

With a passion for astronomy and scientific dissemination, Saulo works as a business administrator in Fortaleza, Brazil. He is the Founder of the Astronomical Events Support Group (GaeA) and hosts Asteroid Day events in observatories, planetariums and astronomy groups throughout Brazil.