**Cosmic Howlers**

March 2023

**TIRED LIGHT?**

…some reaching as fast as 48 million kilometres per hour (44 percent of the speed of light)*. (Astronomy Now, 2012 May, p9)*

## Click to reveal the answer

The speed of light is approximately 300,000 kilometres per second, which is 1,080 million kilometres per hour – 48 million kilometres per hour is therefore 4.4% of the speed of light.

The figure of 44% quoted in the article would make the speed of light much less at 132,000 kilometres per second!

**ANY ROOM FOR ONE MORE?**

…by finding its bright star, Arcturus, which is part of a pattern of stars, or asterism, called the Summer Triangle. *(New Scientist, 2022 May 21, p51)*

## Click to reveal the answer

The **Summer Triangle** is made up of the the three stars **Deneb**, **Vega** and **Altair.**

Each star is the brightest in their constellation: **Deneb** is in **Cygnus** (*The Swan*), **Vega** is in **Lyra** (*The Lyre*) and **Altair** is in **Aquila** (*The Eagle*). Together they form a distinctive pattern (asterism) easily seen in the light summer night sky.

Arcturus (also called *Alpha Boötes*) is the brightest star in the constellation of Boötes (*The Herdsman*) but is **not** part of the Summer Triangle!

**SOME MONSTER!**

M87 is a monster, one of the largest galaxies known. It has a spherical shape measuring 240 light years in diameter.* (The Telegraph, The Night Sky in May 2019)*

## Click to reveal the answer

The diameter of M87 is estimated to be 132,000 light-years – somewhat larger than the 240 light-years quoted in the article!

**A VERY CLOSE SHAVE INDEED**A NASA spacecraft has officially “touched” the Sun, and got to within about eight miles of its core.

*(The Week, 2022 January 8, p13)*

## Click to reveal the answer

The spacecraft in questrion was the * Parker Solar Probe* which flew to within

**3.8 million miles**of the

**Sun’s surface.**Of course, no probe could possibly survive a trip inside the Sun itself!

**THE OLD METHODS ARE CLEARLY THE BEST**

[Olbers’] lifelong concern with comets dates from January 1779, when he used his observations of Bode’s comet to calculate its orbit according to Euclid’s method. *(Dictionary of Scientific Biography, Vol X, p197, 1974)*

## Click to reveal the answer

**Euclid** was an ancient Greek mathematician who lived around 300BC, so he would not have known how to calculate the orbits of comets!

Olbers would have used a method for the calculation of orbits developed by Leonhard Euler, a contemporary of his. Euler’s method employs a first-order numerical procedure for solving the orbital equations using a given initial value.