May this new year be the start of an era of well-being for you and for the planet of life!
The first of the major annual meteor showers should be at its peak in the night between January 3 and 4, mostly after midnight.
The Quadrantid shower is one of the most abundant of the year. Its zenithal hourly rate (ZHR, average number an observer might count per hour at the peak time in a clear dark sky with the radiant overhead) is estimated as 80. But this means the average number that an alert observer might count if the radiant is overhead and sky conditions are perfect. So the actual number you notice is likely to be lower.
The Moon this year is at last-quarter phase. This means that it rises into view about midnight, as does the Quadrantid radiant, and its glare may drown out many of the fainter meteors.
Meteor showers have names derived from the constellations where their radiants are. In this one case, the constellation is a disused one: Quadrans Muralis, the “wall quadrant” (an instrument for measuring the positions of stars), which in old star maps covered an area now assigned to Boötes. If you see, in any part of the sky, a luminous streak that can be traced back to this area near the end star of the Big Dipper, it’s a Quadrantid and not a sporadic bit of space dust.
Showers happen when Earth passes through a stream of particles that follow roughly the orbit of a body from which they were shed, perhaps centuries ago. For most streams the parent body is a comet. The Quadrantids’ parent was long unknown, but in 2003 Peter Jenniskens suggested, from similarity of orbits, that it was asteroid 2003 EH1, discovered in March of that year; and that this might be identified also with a comet recorded by Chinese, Korean, and Japanese observers in December of 1490 and now designated C/1490 Y1.
Asteroids are solid, like tiny planets; comets are small clouds of solids held together by ice which can be vaporized by sunlight, but some may have solid cores which are left looking like asteroids. The orbit of the 1490 comet is given as parabolic (eccentricity 1), but, if the connection with the later phenomena is valid, it must have been of shorter period; it may have disintegrated a century or so later, giving rise to the meteor stream, the asteroid being the remaining core. The great Geminid shower of December is the other one associated with an asteroid, though in a much smaller orbit.
The reason why the Quadrantids start coming into view toward midnight is that the stream meets Earth’s front or morning side. The radiant is well north of, and slightly in front of, the direction in which Earth is traveling at this time, which you can see marked in our sky scene.
Here is the group of four illustrations in the “Meteors” section of Astronomical Calendar 2024. (See the end note about enlarging these diagrams.)
–The space path of the meteor stream, following approximately the orbit of the parent body.
–The area in the map of the sky that contains the radiant.
–Earth’s spinning globe, to show the directions from which sunlight and moonlight and the meteors are coming.
–And the eastern horizon for an American location as the radiant climbs into view in the early night. The radiant will be higher at and after midnight.
______________________________
ILLUSTRATIONS in these posts are made with precision but have to be inserted in another format. You may be able to enlarge them on your monitor. One way: right-click, and choose “”View image”” or “”Open image in new tab”, then enlarge. Or choose “”Copy image””, then put it on your desktop, then open it. On an iPad or phone, use the finger gesture that enlarges (spreading with two fingers, or tapping and dragging with three fingers). Other methods have been suggested, such as dragging the image to the desktop and opening it in other ways.