MAY 2024

Moon phases

PHASE DATE
Third Quarter Wednesday 1st
New Moon Wednesday 8th
First Quarter Wednesday 15th
Full Moon Thursday 23rd

Moon distances    Lunar perigee (closest to Earth) is on Monday 6th at 363,163 km.

Lunar apogee (furthest from Earth) is on Saturday 18th at 404,640 km.

Planets

The planets are 'wanderers' (planeta from ancient Greek) moving along their obits and we can notice them shift their positions against the fixed background of distant stars. Inner planets orbit the Sun faster with shorter years than outer planets which are slower having longer years. The nightly change of position of inner planets, like Mars and Venus, are more obvious than the outer planets, such as Jupiter and Saturn.

Mercury is nearing its greatest elongation (its highest position in our skies). It is visible from 5 am early in the month, rising rise a little later and reaching a slightly lower position during the month before being lost in the dawn light.

Venus is about to move behind the Sun and is not visible this month. Once it completes its passage around the Sun it will return in August in the west after sunset as the 'evening star'.

Mars has returned from its brief trip behind the sun and is visible again from 3:30am as it rises in the north-east.

Jupiter has been nearing the Sun from our perspective and not visible. It is about to pass behind the Sun for its solar conjunction. It will reappear in June in the east around 5:30am.

Saturn is back from its solar conjunction behind the Sun and rises from 2am early in the month, and then a little earlier each morning until from 1am at month's end.

Meteors

The Eta Aquarids meteor shower begins on the 3rd peaking on the 6th. The shower is linked to Comet Halley and rates can reach 55 meteors per hour. They are sand or rice grain size, very fast at 64km/sec, usually yellow with persistent trains, and enter the atmosphere 100km above the surface. They appear in the constellation Aquarius, and the radiant, or point from which they appear to originate, rises at 2.30am moving higher to the north-east by dawn.

Stars and constellations

In the west

The brightest star in the night sky, Sirius, is high in the west and forms the principal star in Canis Major (Greater Dog), a companion to Orion, the hunter who lies below much closer to the western horizon and appears almost upside down from our southern hemisphere view. Marking one of his shoulders is Betelguese, a very obvious red giant star, and diagonally across Orion to the upper left is Rigel, a blue supergiant star that makes a contrast. The three bright stars that form an almost vertical line in the centre of Orion are his belt. His belt is also the base of the 'Saucepan' asterism. His scabbard or sword that angles up from his belt forms the saucepan's handle. In the centre of the handle or sword/scabbard is a fuzzy greenish object which binoculars or telescopes will reveal as the glorious Orion Nebula some 1300 light years from us – a vast cloud of gas and dust where young stars are forming.

Above and to the south of Sirius is Canopus, the second brightest star in the night sky which belongs to the constellation 

In the north

In the north is the constellation of Leo, the lion. Leo is upside down compared to the northern hemisphere. Look for an upside-down question mark as his head and mane. The brightest star in Leo is Regulus, meaning 'little king'.

In the south-east

The large and impressive constellation of Scorpius can now be seen rising horizontally in the south-east with its head and pincers reaching east and the long curving tail stretching to the south. The scorpion's heart is marked by the red star Antares. This is a very rich area of the Milky Way and the scorpion's tail contains beautiful star clusters that can be seen with binoculars.

The two bright Pointers (Alpha and Beta Centauri in the constellation of Centaurus) are low in the south-east and lead your eye up to the smallest constellation astronomers use – Crux (or Southern Cross) which sits on its side this month and easily recognisable.

In less light-polluted skies you can see the pale band of light that arcs across the entire sky from south-east to north-west, the Milky Way, made of billions of distant stars and vast interstellar dust clouds that form much of the galaxy.

In the south-west

Out on their own in the south-west lie the intriguing Large and Small Clouds of Magellan, two small nearby galaxies with names derived from Fernão de Magalhães, the famous Portuguese explorer of the 16th century who attempted the first circumnavigation of the globe, and better known in Spanish as Ferdinand Magellan.

ON THIS DAY

1st 1958, Van Allen radiation belts were discovered - concentrations of electrically charged particles surrounding the Earth influenced by its magnetic field.

1st 1930, Pluto's name is confirmed by Lowell Observatory after a suggestion by British 11-year old Venetia Burney.

1st 1910, birth of astrophysicist J Allen Hynek who investigated reports of unidentified flying objects for the US Air Force under 'Project Blue Book'.

4th 1675, Royal Greenwich Observatory is established by decree of King Charles II.

5th 1961, Alan Shepard Jr (Mercury 3), the first American to be launched into space.

9th 1979, Pioneer Venus 2 craft sent five probes into the atmosphere of Venus.

11th 1916, Albert Einstein's 'General Theory of Relativity' was first presented.

12th 1965, Luna 5 (USSR) crashes on Moon.

13th 1861, one of eight 19th century 'Great Comets' is discovered by John Tebbut.

14th 1973, Skylab 1, USA's first space station was launched.

15th 1618, the Third Law of Planetary Motion, establishing a direct relationship between distance from Sun and orbital period, is determined by Johannes Kepler.

16th 2011, Space Shuttle Endeavour (USA) launched on its 25th and final mission.

17th 1969, Venera 6 (USSR) sends data for 51min before failure due to extreme pressure while descending by parachute to the surface of Venus.

18th 1991, Helen Sharman, the first Briton in space, blasts off onboard a Soyuz spacecraft.

18th 1969, Apollo 10 (USA), the fourth crewed Apollo, launched an 8 day full rehearsal mission without a moon landing. It sent the first colour TV to Earth and orbited the moon 31 times. With Command Module 'Charlie Brown' in orbit, Lunar Module 'Snoopy' flew for two hours in four orbits coming to14km of the surface after which its descent (lower) stage was jettisoned to eventually crash on the moon, and later its ascent (upper) stage was sent into space to orbit the sun.

18th 2005, Pluto's moons Nix and Hydra are seen by Hubble Telescope before New Horizons' (USA) later discovery of two more, Styx and Kerberos.

19th 1961, Venera 1 (USSR) makes first pass of a planet (in this case Venus) although contact with Earth by then had been lost.

20th 1990, Hubble Space Telescope sent its first photograph from space, an image of a double star 1,260 light years away.

21st 2010, launch of IKAROS spacecraft (Japan), the first successful solar sail technique used for planetary travel.

25th 1961, President John F. Kennedy launches the USA's race to the Moon.

25th 240 BCE, first recorded close pass by the Sun (perihelion) of Comet Halley.

28th 1959, monkeys Abel and Baker are sent on sub-orbital flight of 580 km into space in the nose-cone of a Jupiter rocket.

28th 585 BCE, solar eclipse occurs during a battle between Medes and Lydians. Knowledge of past eclipses has enabled dating of other historical events.

28th 2002, water ice on the Red Planet is discovered by Mars Odyssey (USA).

29th 1919, Einstein's 'General Theory of Relativity' is confirmed by Arthur Eddington's study of distant star light bending during a total solar eclipse.

29th 1794, birth of the first astronomer to map the Moon and Mars, Johann von Mädler.

30th 1975, European Space Agency (ESA) is created by merging Launch Development and Space Research organisations.

30th 1966, launch of Surveyor 1 (USA) which will make the first landing on another body; in this case, the Moon.