Stargazers with backyard telescopes may notice something amiss in the night sky this weekend as a rare planetary alignment produces a mind-boggling optical illusion.<\/p>\n
On Sunday, November 23, Saturn\u2019s iconic rings will almost completely disappear<\/a>. Don\u2019t worry, the billions of chunks of rock and ice that circle this gas giant won\u2019t actually be gone, but they will temporarily look invisible to us Earthlings. That\u2019s because Saturn will align with Earth so that its rings face us edge-on. Since they\u2019re so thin, we\u2019ll no longer be able to see them clearly.<\/p>\n This happens every so often due to the fact that Saturn leans at an angle of 26.7 degrees. That means its rings shift up and down as it orbits the Sun. When Saturn\u2019s rings are visible to Earth\u2014which they are most of the time\u2014we\u2019re looking at the flat plane of the rings tilted toward us, making them appear broad and bright in the night sky.<\/p>\n This weekend\u2019s alignment won\u2019t result in a total vanishing of Saturn\u2019s rings, but they will appear to narrow to less than 1% visibility before the relative positions of the two planets make them appear to widen out again, according to the New York Times<\/a>.<\/p>\n A rare cosmic illusion <\/p>\n Saturn\u2019s ring system extends up to 175,000 miles (282,000 kilometers) out from the planet. Relative to that width, they\u2019re extremely thin, with a vertical height of only 30 feet (10 meters) in the main rings.<\/p>\n The edge-on alignment between Earth and Saturn occurs every 13 to 15 years when Earth passes through Saturn\u2019s ring plane. This is actually the second time it\u2019s happened this year, with the first instance occurring on March 23<\/a>.<\/p>\n During one of these events, Saturn\u2019s rings typically remain invisible for about a week. After they reappear later this month, we won\u2019t get to see this illusion again until October 15, 2038, according to NASA<\/a>.<\/p>\n Though these periodic vanishing acts are nothing more than a trick of angles, Saturn is actually losing its rings, albeit very slowly. The material that makes up the rings is being pulled into Saturn by its own gravity as a dusty rain of ice particles. Data collected by NASA\u2019s Cassini spacecraft, which flew through Saturn\u2019s rings in 2017<\/a>, suggests they could disappear<\/a> for real in 100 million years.<\/p>\n You certainly won\u2019t be around to see that happen, but if you\u2019d like to experience this weekend\u2019s ring plane crossing, here\u2019s what you need to know.<\/p>\n How to see Saturn naked <\/p>\n Saturn will be visible in the southeastern sky after sunset over the weekend, but you\u2019ll need to use a telescope to see it without its rings. Any small backyard telescope will do.<\/p>\n The rings will look thinnest at 7 p.m. ET on Saturday, according to the New York Times<\/a>, but you\u2019ll be able to see the edge-on effect if you look before 3:30 a.m. local time on Saturday or Sunday, when Saturn sets from the night sky.<\/p>\n