The Geminids are a prolific

meteor shower A meteor shower is a celestial event in which a number of meteors are observed to radiate, or originate, from one point in the night sky. These meteors are caused by streams of cosmic debris called meteoroids entering Earth's atmosphere at ext ...

with

3200 Phaethon 3200 Phaethon (; previously sometimes spelled Phæton), provisionally designated , is an active Apollo asteroid with an orbit that brings it closer to the Sun than any other named asteroid (though there are numerous unnamed asteroids with sm ...

(which is thought to be an

Apollo asteroid The Apollo asteroids are a group of near-Earth asteroids named after 1862 Apollo, discovered by German astronomer Karl Reinmuth in the 1930s. They are Earth-crossing asteroids that have an orbital semi-major axis greater than that of the Ear ...

with a " rock comet" orbit.) being the parent body. Because of this, it would make this shower, along with the

Quadrantids The Quadrantids (QUA) are a meteor shower that peaks in early January and whose radiant lies in the constellation Boötes. The zenithal hourly rate (ZHR) of this shower can be as high as that of two other reliably rich meteor showers, the Persei ...

, the only major meteor showers not originating from a

comet A comet is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or Coma (cometary), coma surrounding ...

. The

meteor A meteor, known colloquially as a shooting star, is a glowing streak of a small body (usually meteoroid) going through Earth's atmosphere, after being heated to incandescence by collisions with air molecules in the upper atmosphere, creating a ...

s from this shower are slow, they can be seen in December and usually peak around December 4–16, with the date of highest intensity being the morning of December 14. Current showers produce up to 120–160 meteors per hour under optimal conditions, peaking around 2:00 or 3:00. Geminids were first observed in 1862, much later than other showers such as the

Perseids The Perseids are a prolific meteor shower associated with the comet Swift–Tuttle that are usually visible from mid-July to late-August. The meteoroid, meteors are called the Perseids because they appear from the general direction of the const ...

(36 AD) and

Leonids The Leonids ( ) are a prolific annual meteor shower associated with the comet 55P/Tempel–Tuttle, Tempel–Tuttle, and are also known for their spectacular meteor storms that occur about every 33 years. The Leonids get their name from the loca ...

(902 AD). Based on data from the

Parker Solar Probe The Parker Solar Probe (PSP; previously Solar Probe, Solar Probe Plus or Solar Probe+) is a NASA space probe launched in 2018 to make observations of the Stellar corona, Sun's outer corona. It used repeated Gravity assist, gravity assists from ...

, a 2023 study suggested that the Geminids may have been formed by the catastrophic breakup of a comet that formed asteroids 2005 UD and 1999 YC in addition to Phaethon.

Background

The Geminid meteor shower is unique among celestial events as it originates not from a comet but from the asteroid 3200 Phaethon, discovered on Oct. 11, 1983, by the Infrared Astronomical Satellite (IRAS). Phaethon's 1.4-year orbit around the

Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

and its comet-like elliptical trajectory have led scientists to speculate if it is a "dead comet" or a distinct celestial entity known as a "rock comet." Despite its comet-like orbit, Phaethon lacks a cometary tail and exhibits spectra resembling a rocky asteroid. The Geminid meteoroids formed from Phaethon are denser (2–3 g/cm³) than typical cometary dust flakes (0.3 g/cm³). Named after the Greek mythological figure who drove the Sun-god Helios' chariot, Phaethon's discovery was attributed to astronomer Fred Whipple.

Radiant

The meteors in this shower appear to come from the radiant in the constellation

Gemini Gemini most often refers to: * Gemini (constellation), one of the constellations of the zodiac * Gemini (astrology), an astrological sign Gemini may also refer to: Science and technology Space * Gemini in Chinese astronomy, the Gemini constellat ...

(hence the shower's name). However, they can appear almost anywhere in the night sky, and often appear yellowish in hue. Well north of the equator, the radiant rises about sunset, reaching a usable elevation from the local evening hours onwards. In the southern hemisphere, the radiant appears only around local midnight or so. Observers in the northern hemisphere will see higher Geminid rates as the radiant is higher in the sky. The meteors travel at medium speed in relation to other showers, at about , making them fairly easy to spot. They usually fall apart while at heights above . Meteor falling courtesy NASA

Timeline

References

External links

Viewing details for the 2015 Geminids Meteor Shower

* NASA Meteor Watch 2012: *
Allsky cameras observed 328 bright Geminids – notice how similar they are to the orbit of the asteroid 3200 Phaethon (purple orbit)
*
Composite view of meteors detected in the skies over Marshall Space Flight Center (MSFC)
*
Spectacular Geminid, brighter than the Full Moon
(video 2012-Dec-14 07:28 UT) *
Meteoroid Environment Office: 53 meteor orbits last night of which 18 were Geminids

*

" NASA, 7 December 2001 * Google group search fo
Geminids
sorted by date
Amateur observations of the Geminids

Triangulation of a Geminid Meteor by Crayford Manor House AS

ScienceCasts: Rock Comet Meteor Shower
(Science@NASA YouTube channel : Nov 29, 2012)
Geminids at Constellation Guide
* {{Meteor showers Meteor showers December

Background

Radiant

Timeline

See also

References

External links