Skynotes July 2017

Skynotes

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Month Highlights

Jupiter and Saturn continue to shine brightly in the evening sky. Towards the end of the month Mercury joins the two gas giants and appears low in the north-west after sunset. Venus is the only planet in the early morning sky, but it is lovely and bright in the north-east.

Planetarium Events

Discover the Night Sky

The Melbourne Planetarium at Scienceworks presents its popular after-dark sessions in August. All evenings include a glass of wine with cheese, the opportunity to chat to the Planetarium’s astronomer, Dr Tanya Hill, and to be immersed in a planetarium experience. You will finish the evening stargazing through telescopes (weather permitting).

Each evening will showcase a different aspect of the night sky. For more information, pricing or bookings please see the What's On or call the Scienceworks Booking Office on 9392 4819.

Sunrise and Sunset Times

Date Rise Set
Saturday 1st 7:36 5:11
Tuesday 11th 7:34 5:17
Friday 21st 7:29 5:24
Monday 31st 7:21 5:31

Moon Phases

Phase Day Date
First Quarter Saturday 1st
Full Moon Friday 9th
Last Quarter Saturday 17th
New Moon Sunday 23rd
First Quarter Monday 31st

The Moon will be at apogee (furthest from Earth) on Thursday 6th at a distance of 405,932 km.

The Moon will be at perigee (closest to Earth) on Saturday 22nd at a distance of 361,236 km.

Let The Moon Be Your Guide

The Moon can be used as a pointer to find other objects in the sky.

  • The First Quarter Moon is just below Jupiter on the night of the 1st.
  • After sunset on the 7th, the waxing gibbous Moon is below Saturn.
  • Before sunrise on the 20th, the waning crescent Moon is very close to Aldebaran (Taurus, the bull).
  • Then on the 21st, bright Venus sits just above the crescent Moon.
  • After sunset on the 25th, the waxing crescent Moon is below Mercury and Regulus (Leo, the lion).
  • On the evening of the 29th, the crescent Moon joins Jupiter and Spica (Virgo, the maiden).

Planets

Mercury returns to the evening twilight sky later in the month. On the 25th, Mercury can be found to the left of the bright star Regulus (Leo, the lion) and a lovely crescent Moon will sit below them.

Venus is eye-catching in the early morning sky. It is slowly drifting back towards the north-east horizon. On the 13th, Venus will be directly to the left of the orange giant star Aldebaran (Taurus, the bull). Then on the 21st the thin crescent Moon will sit just below Venus.

Earth reaches aphelion on Tuesday 4th. This is when the Earth is at its furthest point from the Sun for the year, at 152 million km. It is a coincidence that this occurs during our winter; the change in distance between the Earth and Sun during one orbit is small enough that there is no significant effect on daily temperatures.

Mars is too close to the Sun to be seen this month.

Jupiter is high in the north at sunset and can be seen in the north-west later in the evening. On the 1st, the First Quarter Moon is just below Jupiter. Then on the 29th the crescent Moon forms a triangle with Jupiter and the bright star Spica (Virgo).

Saturn is found in the north-east at sunset sitting below the constellation of Scorpius. In fact, it is positioned near the centre of our Galaxy, the brightest and also the dustiest part of the Milky Way. The Moon is just below Saturn on the night of the 7th.

Meteors

While July doesn’t have any strong meteor showers, there are a number of minor showers that combine to produce good results during the later half of the month. The area of sky to watch is around the constellations of Aquarius and Capricornus and as always, the best time to spot meteors is after midnight. The main meteor shower for July, the Southern Delta Aquarids, peaks on the 28th.

Stars and Constellations

In the west in the early evening is the kite shape of Corvus, the crow, sitting just below the bright star Spica, in Virgo. The Southern Cross is high in the south while the bright stars Canopus and Achernar are found low to the southern horizon.

Almost overhead, Scorpius takes up a large part of the sky with the hook shape of its tail. Sitting below the tail of Scorpius is the teapot shape of Sagittarius.

International Space Station

From Earth, the ISS appears as a bright star that steadily moves across the sky. It can often be seen from Melbourne, for example at:

6:18pm – 6:23pm, Monday 3rd July.

The Station will travel above the south-west horizon, passing by the two brightest stars in the night sky - Sirius (Canis Major) and Canopus (Carina).

Predictions of when to see the ISS can be obtained from the Heaven's Above website.

On This Day

4th 1997Mars Pathfinder (USA) lands on Mars.

4th 1054, Chinese and other astronomers witnessed the supernova explosion that produced the Crab Nebula.

6th 1687, Isaac Newton (UK) published 'Principia Mathematica'.

8th 2011, The space shuttle Discovery (USA) was launched on the final mission for the shuttle program.

10th 1962Telstar (USA) the first private telecommunications satellite was launched.

11th 1979Skylab 1 (USA) was destroyed during re-entry over central Australia.

14th 1965Mariner 4 (USA) made the first controlled flyby of Mars and returned the first close-up images of the planet.

15th 1975, the first USA/USSR space project Apollo-Soyuz was launched.

17th 1850, W.C. Bond and J.A. Whipple (USA) take the first photograph of a star.

20th 1969Apollo 11 (USA) lands on the Moon. At 12:39pm AEST (21st) Neil Armstrong became the first person to walk on the Moon.

23rd 1999, The Chandra X-ray Observatory (USA) is launched from the space shuttle Columbia.

25th 2000, The International Space Station starts to take shape with the installation of the Russian Service Module.