The bizarre solar phenomenon that hits an Australian region just TWICE a year - so can you see what's so different about these pictures? Just after midday on Tuesday shadows vanished in Northern Territory capital The phenomenon happens twice a year in Darwin and a handful of other places Shadows disappear for a few minutes as the sun's rays are at exactly 90 degrees By Brett Lackey For Daily Mail Australia Published: 05:51 BST, 26 October 2021 | Updated: 05:51 BST, 26 October 2021 Viewcomments An Australian region has witnessed a bizarre solar phenomenon that happens twice a year for just minutes in only a handful of countries on Earth. In Darwin at 12.30pm on Tuesday the sun's rays were exactly perpendicular to the planet causing shadows on the ground to completely disappear. The alignment happens twice a year - on different dates for each location - in Darwin, Cairns and Townsville in Australia and in some other places such as Hawaii where the event is called Lahaina Noon. The phenomenon at Darwin Airport showing shadows disappearing from a road sign (pictured) Twice a year Darwin gets the sun's rays at exactly right angles to the ground (pictured) 'As the Earth zips around the sun, one side is always in daylight, and there's always a point on the Earth's surface where the sun is directly overhead,' the Bureau of Meteorology's Jackson Browne explains. 'This is known as the subsolar point - when the Sun's rays are perpendicular, or at exactly 90 degrees.' For the most part this is over water but there are occasions when the phenomenon travels over land. 'At this point in time the shadows of trees, buildings, people, and in fact any object are at their shortest.' Because of the angle at which the Earth tilts the sun's rays can only be perpendicular as far north as the Tropic of Cancer and as far South as the Tropic of Capricorn. This is why shadows will only disappear in tropical areas such as Darwin, Townsville and Hawaii. In Hawaii the event is known as Lahaina Noon (pictured). There are only a handfuls of countries where this happens A Darwin local showing her the sunlight directly vertical at just after midday on Tuesday (pictured) Some Darwin residents had already posted by Tuesday afternoon that they went outside and their shadows did indeed disappear. 'This is so cool,' one person wrote. 'This worked! Sun went behind a cloud and had to wait though, ' added another. 'I remember this used to be our annual experiment before December holidays at school,' a third said. Darwin will get their next subsolar point on February 16, while Cairns will have one on November 9 and February 2. Townsville will have theirs on November 18 and January 24. This image from Tuesday shows the shadows disappearing on this Darwin Street (pictured) A streetlight with road signs attached casting a shadow directly underneath in Darwin (pictured) Share or comment on this article: All rights reserved for this news site (dailymail) and under his responsibility