Welcome to the April night sky. Soon after sunset, over in the west, the brilliant planet Venus is easily visible low on the horizon, and on the evening of the 17th the thin crescent Moon will be seen near to Venus. Before midnight, the gas giant planet Jupiter can be seen rising in the east in the constellation of Libra.
Next month this king of planets is at opposition to the Sun and this means it will be at its closest and brightest. When Jupiter is at opposition, it will be visible all night and, through any small telescope, the cloud belts and four large Moons are visible.
About two hours after Jupiter has risen, the planets Saturn and Mars can be seen rising from the southeast horizon in the constellation of Sagittarius. Mars and Saturn are of similar brightness but different colours. Saturn is a pale-yellow colour, but Mars is called the red planet, although it is an orange colour as seen with unaided eye.
The month of April has many minor meteor showers but the most reliable is the Lyrids on the night of the 22nd. This meteor shower is made up from dust left over from the tail of comet Thatcher that was last seen in the year 1861. This shower has been known about and followed since the year 687 BC. The origin point for the Lyrids is close to the bright star Vega.
Curiously, the month of April is well known for very bright meteors called fireballs and the origin of these spectacular objects is a mystery as they can appear at any time of the night and have an origin from any point in the sky. These fireballs have been known to survive the fall through the atmosphere of the Earth and hit the ground as meteorites.
If you saw one of these objects on the ground, they would likely be small and produce a crater about 10 times larger than their diameter. Some meteors can be quite valuable, especially if they can be determined chemically to come from Mars or the Moon.
A newly-fallen meteor would be dark in colour and initially be very hot to touch; but quickly it would be covered in a layer of frost as the inside would be below zero due to the low temperature experienced in space.
The Moon is last quarter on the 8th, new on the 17th, first quarter on the 22nd and full on April 30.
By Clive Jackson
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Clive Jackson is the Director of the Camera Obscura (next to the Castle in Tavira), specialising in education and public outreach.
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To see the April Sky Map click on the pdf link below