Visible Planets September 2015 – Mercury and Venus


We’re still here, asking about the visible planets and which ones we might see.  Kam just loves the planets and is desperate for a telescope! We’re saving and have been for a while as I’d like to get a reasonable one.


Mercury: NASA
Mercury: NASA

Mercury, closest planet to the Sun,  it orbits the Sun in 88 days.  So, a Mercury year is 88 Earth days long.

Now, a Mercury day is 176 Earth days long! It spins or rotates very slowly on its own axis.

NASA have had two ventures to explore Mercury.

One was in 1973/5, a NASA probe Mariner 10 gathered information about Venus and then Mercury.  Mariner 10 sent back images of Mercury’s surface and other scientific information.  It’s transmitter  was turned off on March 24 1975.  Scientists believe it still orbits the Sun.

Mercury’s final image transmitted to Earth: NASA

Between 2004 and 2015, another NASA probe Messenger sent information about Venus and Mercury. It studied Mercury from 2011, sending 250,000 images and vast amounts of data. It orbited Mercury and verified Scientists beliefs that Mercury’s Polar regions contained ice deposits of water.
Messenger crashed on April 30 2015 at 1926 GMT.  Finally Mercury’s gravity brought it down to rest.

Mercury – as at September 2015

On September 4 Mercury is in elongation East – this means it is as its furthest distance from the Sun as seen from Earth, East means it is an evening star.

However, we’re out of luck,  we will not see Mercury as it barely rises above our horizon.


Venus: NASA
Venus: NASA

Venus is an inferior planet that is it is closer to the Sun than Earth.  (Mercury is the other inferior planet.)

Venus rotates backwards (clockwise) compared to the other planets.  This means the Sun would rise in the West and set in the East.  Venus rotates on itself so slowly that sunrise in the west does not see its sunset in the east, wait for it, until 116 Earth days later!

Note: a rotation is an object which spins once on its own axis.

Venus from Messenger: NASA

Venus has had many missions to it.  In 1962, NASA’s Mariner 2  reached 34,000km from Venus and recorded Venus’s very hot temperature of 462°C.

The Soviet (Russian) Venera 7 landed on Venus on December 15 1970.  It was the first the first spacecraft to land on another planet, it landed awkwardly and sent weak signals to Earth.  Before landing it sent data back to Earth, including information giving Venus’s atmosphere at 97% carbon dioxide.

Venus venera9
Venus from Venera 9: NASA

Venera 9 landed on Venus on October 20 1975.  Just before landing it sent the first images of another planet’s surface.

The ESA’s first mission to Venus was the Venus Express.  It launched in 2005 and its mission ended in November 2014.

There have been many missions to Venus.

Venus – as at September 2015

Venus is visible in the dawn sky. It rises about 5am, 1 and a 1/2 hours before the Sun rises.  It fades as dawn breaks.  It rises from the Eastern horizon.

It is so close to the Sun, that it is not safe to view at or after sunrise.

Jupiter and Venus, June 30th
Jupiter and Venus, June 30th: Kam and Mum.

Jupiter is yellowish and at the top, with Venus brilliant and bright at the bottom.  Kam had had a late night and for a few extra extra minutes he saw Venus and Jupiter.  He was so pleased and loves this photo.  

A Note to You and Me

These notes are for Kam and I to find planets and to know which planets we can see.

Back to telescopes, I keep looking at a Dobsonian 200P. I really would welcome any advice and on what accessories we’d need and if we are looking at the right telescope.  I have read reviews and advice pages, yet seem to re-read them many times!

Mercury and Venus are two of the five visible planets from Earth.  We have another post for Mars, Jupiter and Saturn.  We’ll add the link as soon as we post the post!

As always, thanks for reading and if you like it like us!


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