BBC Sky at Night

Where is the ‘square kilometre’?

SKA director Phil Diamond admits that ‘Square Kilometre Array’ is a bit of a misnomer. The 197 dish antennas of SKA-Mid in South Africa have a total surface area of 33,000m2 (0.033km2). The effective receiver surface area of the dipole antennas of SKA-Low in Australia can be calculated with a complicated formula that is dependent on the observing frequency; it's in the order or 0.4km2. However, the name – Square Kilometre Array’ was conceived in the late 1990s, with the future second phase of the facility in mind, which will have 10 times the number of dishes and antennas. “If that second phase will indeed be realised in the future, we will easily reach a total

You’re reading a preview, subscribe to read more.

More from BBC Sky at Night

BBC Sky at Night1 min read
Parker's Design Features
To withstand the extreme heat and radiation found in our star’s immediate neighbourhood, Parker Solar Probe is protected by a 2.3-metre-diameter (7.5ft) hexagonal solar shield, weighing just 73kg (160lb) and mounted on its Sunfacing side. This shield
BBC Sky at Night7 min read
Touching the SUN
On 12 August 2018, NASA’s Parker Solar Probe (PSP) blasted off from Cape Canaveral Air Force Station into the pre-dawn Florida sky on a mission to become the first-ever spacecraft to ‘touch the Sun’. Later this year, on 24 December 2024, Parker will
BBC Sky at Night2 min read
Binocular Tour
10 x 50 In the days before Herman Snellen introduced his eponymous eye-test chart, mag. +2.2 Mizar (Zeta (ζ) Ursae Majoris) and mag. +4.0 Alcor (80 Ursae Majoris) were used as an eyesight test: if you couldn’t see two stars, you knew you needed spect

Related Books & Audiobooks