Of the chondrites, the most important scientifically are the carbonaceous chondrites, like the Winchcombe meteorite. Apart from the chondrules, these may contain organic material (such as amino acids), water and pre-solar grains. These compounds are essential for life, and there is an opinion that life on Earth has arisen because these materials have been delivered by carbonaceous meteorites or carbonaceous minor planets that have impacted on the Earth. The result of this behaviour was a highly complex pattern, which proved difficult to explain on a geocentric model.

2023 Night Sky Almanac | Astronomy Technology Today

Observers at 50°N may occasionally be able to detect bright Deneb (α Cygni) and Vega (α Lyrae) skimming the horizon, together with portions of those particular constellations, although most of the time they will be lost in the extinction that occurs at such low altitudes. This ebook contains the following accessibility features which, if supported by your device, can be accessed via your ereader/accessibility settings: The charts in this book are designed to be used more-or-less anywhere in the world. They are not suitable to be used at very high northern or southern latitudes (beyond 60°N or 60°S). That is slightly less than the latitudes of the Arctic and Antarctic Circles, beyond which there are approximately six months of daylight, followed by six months of darkness. The design may seem a little complicated, but these diagrams should make their usage clear. The main charts are given in pairs, one pair for each month: Looking North and Looking South. Mercury is essentially invisible in twilight. Venus is bright (mag. -3.9) and will become visible in the evening sky towards the end of the month. Mars is in Taurus and fades from mag. -0.3 to mag. 0.4 over the month. Jupiter, in Pisces, is mag. -2.1, but Saturn is in Aquarius, much closer to the Sun, and will be lost in twilight. Uranus remains in Aries at mag. 5.8, and Neptune is in Pisces at mag. 7.9 to 8.0, close to evening twilight.The initial object (a small asteroid) was estimated to have a diameter of about 20 metres and approached from the direction of the Sun, which is why it was not detected before arrival. Following the airburst, some fragments survived to reach the ground, west of Chelyabinsk. The snow-covered ground made the recovery of these relatively easy. Most, however, found their way into private hands. The largest known fragment was eventually recovered from the frozen Lake Cherbakul after a long recovery process. This proved to have an initial mass of 654 kg. All the recovered meteorites were found to be ordinary stony chondrites (see here). The use of the epicycle and deferent was developed and propagated by the great astronomer Ptolemy (approximate dates 100 to 170 CE), who found that he had to introduce further terms, which he denoted the ‘eccentric’ and the ‘equant’. This further complicated the situation, and these terms are not explained here. Although the positions of the various shower radiants are shown on the charts, looking directly at the radiant is not the most effective way of seeing meteors. They are most likely to be noticed if one is looking about 40–45° away from the radiant position. (This is approximately two hand-spans as shown in the diagram for measuring angles here.) The First Point of Aries is sometimes known as the Cusp of Aries, and the equinox in September as the Cusp of Virgo.

2023: Night sky events not to miss - EarthSky Best of 2023: Night sky events not to miss - EarthSky

Somewhat similarly, at a lunar eclipse, the Moon may pass through the outer zone of the Earth’s shadow, the penumbra (in a penumbral eclipse, which is not generally perceptible to the naked eye); pass so that just part of the Moon is within the darkest part of the Earth’s shadow, the umbra (in a partial eclipse); or completely within the umbra (in a total eclipse). Unlike solar eclipses, lunar eclipses are visible from large areas of the Earth. Again, these are described in detail in the relevant month. This month the constellation of Carina is well placed for observers at 20°N or more to the south. Canopus (α Car) is the second brightest star in the sky. Avior (ε Car) and Aspidiske (ι Car) form the False Cross, together with two stars that belong to the constellation of Vela: Alsephina (δ Vel) and Markeb (κ Vel). The small constellation of Volans is almost embedded in Carina. This month the constellations Lyra and Cygnus are seen almost overhead as darkness falls with their bright stars Vega, in Lyra, and Deneb, in Cygnus, making up the "summer triangle" of bright stars with Altair in the constellation Aquila below. (see sky chart above) LyraLearn more about the full Moons of August, how they got their name, and best days by the Moon in our August Moon Guide. Every year I see this book come up on Netgalley and every year I request this and then go and find myself a physical version, as these impressive but compact books give us another guide to the stars for the year coming that always impresses me. At the equinox in March and again, in September, the Sun rises due east and sets due west. In theory, but not in practice, day and night are of equal length (see here). At the equinoxes, the Earth’s axis is exactly at right angles to the Earth–Sun line, and the Earth is neither tilted towards, nor away from the Sun. The constellation of Auriga, with brilliant Capella which, although appearing as a single star, is actually a quadruple system, consisting of a pair of yellow giant stars, gravitationally bound to a more distant pair of red dwarfs. Elnath, near the bottom, actually belongs to the constellation of Taurus. February 3 • The Moon forms a nice, almost isosceles, triangle with Pollux and Castor (as seen from Sydney).

Night Sky Almanac 2023: A stargazer’s guide – HarperCollins Night Sky Almanac 2023: A stargazer’s guide – HarperCollins

August 30: Saturn hovers just above the Full Moon after nightfall. As Saturn’s at its best, it’s now easiest to identify with the Moon as aguide. It’s the best of 2023! Mark your calendars for the best stargazing events for the upcoming year. From planetary pairings to a partial solar eclipse, there’s much to look forward to. As it passes across the sky from west to east in its orbit around the Earth, the Moon moves by approximately its diameter (about half a degree) in an hour. Normally, in its orbit, the Moon passes above or below the direct line between Earth and Sun (at New Moon) or outside the area obscured by the Earth’s shadow (at Full Moon). Occasionally, however, the three bodies are more-or-less perfectly aligned to give an eclipse: a solar eclipse at New Moon, or a lunar eclipse at Full Moon. Depending on the exact circumstances, a solar eclipse may be merely partial (when the Moon does not cover the whole of the Sun’s disc); annular (when the Moon is too far from Earth in its orbit to appear large enough to hide the whole of the Sun); or total. Total and annular eclipses are visible from very restricted areas of the Earth, but partial eclipses are normally visible over a wider area. Two forms of solar eclipse occur this year, and are described in detail in the appropriate month. Why does February have such an odd number of days, and why do we tinker with it every four years? The answer is suprisingly complicated, and involves the ancient Roman lunar calendar, Roman emperors, including Julius Caesar, the Roman Senate, the priests, and the way in which politicians messed about with the calendar, and how we have avoided even greater confusion. A fairly comprehensive description of how these changes came about is given here.

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The contents of this publication are believed correct at the time of creation. Nevertheless the Publisher can accept no responsibility for errors or omissions, changes in the detail given or for any expense or loss thereby caused. Ursa Minor, also with seven main stars, one of which is Polaris, the Pole Star, and the long constellation of Draco that winds around the Pole, are readily visible for anyone in the northern hemisphere, although, of course, Polaris is right on the horizon for anyone at the equator, and thus always lost to sight. Cepheus is near the meridian to the north, with Cassiopeia, to its west beginning to turn and resume its ‘W’ shape. The constellation of Andromeda is now diving down into the northwestern sky. In the east, beyond Alkaid (η Ursae Majoris), the final star in the ‘tail’ of Ursa Major, lies the top of Boötes. Farther to the south, most of Hercules and the ‘Keystone’ shape that forms the major portion of the body is visible. The main ‘upright’ of Crux, if extended and curving slightly to the right, does point in the approximate direction of the Pole, passing through Musca and the tip of Chamaeleon. However, a better way is to start at Hadar (the star in the bright pair that is closest to Crux), turn at right-angles at Rigil Kentaurus, and following an imaginary line through the brightest star in the small constellation of Circinus and then right across the sky, brushing past the outlying star of Apus, and the star (δ) at the apex of Octans itself.