ESA is standardising comparisons for Near Earth Asteroids

RockDoctor writes: In this month's ESA Near Earth Object Coordination centre Newsletter, they propose an number of standardised units of comparison for journalists describing "death from the skies" :

Let’s look at some of our favourite unusual suspects:

• Corgi: At around 30 cm tall, a space rock the size of a corgi wouldn’t pose much of a threat.
• Half a giraffe: An adult giraffe can reach up to 5.5 metres in height, so half a giraffe would be about 2.75 metres. While not as impressive as a full skyscraper (themselves varying in size by more than an order of magnitude / 2.5 astronomical magnitudes ; 0.3 geological magnitudes), an asteroid that size could certainly destroy a building or two.
• Peacock: Male peacocks, with their extravagant tails, can reach up to 3 metres in length. Six peacocks in a line would stretch 18 metres, big enough to cause localised damaged. This is also the size of 15 alpacas standing shoulder to shoulder. (There is no International Standard Alpaca. Yet.)
• Elephants: An adult African elephant can reach 7 metres at the shoulder. Ninety elephants stacked on top of each other would form a staggering pile over 630 metres high, creating a devastating but probably not planet-ending event.

In consequence of this continuing confusion, the ESA recommend :

the use of a Standardised Giraffe Unit (SGU, 1 SGU = 5 penguins) for ease of comparison.

As frequently pointed out, defining units can be difficult. It has already been pointed out that the penguin itself is poorly defined, a herring-and-finger-replete seated Adelie penguin being substantially different to an aroused Emperor. Others have pointed out that such standardisation should be done at the IAU level, since Americans don't attend international meetings due to TSA gropings. Personally, I note that the reference frame and any Lorentz contraction of the penguin is undefined. But it's an invaluable start, nonetheless.

Returning to it's normal topic, the Newsletter points out that :

A large asteroid will fly-by the Earth and become relatively bright this month. (439437) 2013 NK4 is a large asteroid, roughly 100 SGU in diameter, which will approach our planet about 8 times as far as the Moon on 15 April, reaching magnitude 12.

That's a mere 250 times dimmer than the human eye can see, so opening your (eye) pupils to about 100mm diameter should make it easily visible. (Mechanical details are left as an exercise for the reader.)

The world may be turtles all the way down, but it's giraffes all the way up.