{"id":350,"date":"2011-02-06T10:03:15","date_gmt":"2011-02-06T17:03:15","guid":{"rendered":"http:\/\/invertedsky.net\/?p=350"},"modified":"2011-02-06T10:26:23","modified_gmt":"2011-02-06T17:26:23","slug":"very-large-array-vla","status":"publish","type":"post","link":"https:\/\/invertedsky.net\/?p=350","title":{"rendered":"Very Large Array (VLA)"},"content":{"rendered":"

There are probably a myriad of reasons I’ve been infatuated with the Very Large Array in New Mexico.\u00a0 I finally was able to visit the VLA on my westward journey on U.S. Highway 60 from Socorro, New Mexico.<\/p>\n

Simply put, the VLA is an array of 27 radio telescopes which are all connected together to emulate a huge radio telescope that is up to 22 miles in diameter.<\/p>\n

I first became acquainted with the VLA in the movie “Contact” where it is used to receive extra terrestrial communications.\u00a0 (For other pop culture references, click here<\/a>.)\u00a0 In real life, it doesn’t do that.\u00a0 Instead, it receives signals that optical telescopes can’t see.\u00a0 The scientists don’t “listen” to the VLA, the VLA creates images.<\/p>\n

\"\"<\/a><\/p>\n

I stopped into the deserted visitor center on a cold but clear Saturday morning.\u00a0 After chatting with the woman staffing the post and looking at the exhibits, I went on the self-guided walking tour of the facility.<\/p>\n

<\/p>\n

\"\"<\/a><\/p>\n

As I mentioned earlier, there are 27 of these dishes (with plans for expansion to 33) all arranged in a large “Y”.\u00a0 Each dish is huge at 82 feet in diameter and weighs over 200 tons.\u00a0 There are motors that point the antenna to the proper place in the sky.\u00a0 All of the dishes change position at the same time to point at the same part of space.<\/p>\n

\"\"<\/a><\/p>\n

These dishes are constantly moving, sometimes slowly to compensate for the earth’s rotation, sometimes much faster to point at a different location in space.\u00a0 While I was standing next to this dish, it would point to a new location about every 30 seconds.\u00a0 And, when I looked at the other dishes in the distance, I could see them moving too.<\/p>\n

\"\"<\/a><\/p>\n

The radio signals hit the dish and are then reflected up to another reflector that’s mounted above the dish.\u00a0 This concentrates the radio beam and reflects it again down into the thing that looks like a cone (called a horn).<\/p>\n

\"\"<\/a><\/p>\n

There are actually 6 or 7 horns of different sizes, each one is sensitive to a certain type of signal.\u00a0 The largest horn is about 7 feet tall to give you a perspective on size.\u00a0 From there the radio signal is converted to digital and it sent via fiber optics to the “correlator” in the control building which combines the signals from all of the antennas.<\/p>\n

\"\"<\/a><\/p>\n

The length of each leg of the “Y” can be adjusted, which acts like a zoom, by moving the dishes farther apart or closer together.\u00a0\u00a0 These dual railroad tracks are used for that. \u00a0 The configuration of the array is changed every few weeks.\u00a0 There is an interesting video in the visitor center that shows it being done.\u00a0 To move a dish, it is unbolted from cement pylons and lifted by a special a machine and moved along the tracks to the new position.<\/p>\n

\"\"<\/a><\/p>\n

Although the VLA is not used for extraterrestrial searches like in the movies, I’m sure if an alien world was broadcasting a signal, the VLA would eventually find it.<\/p>\n

I spent several hours at the VLA site before heading westward on my trip.<\/p>\n","protected":false},"excerpt":{"rendered":"

There are probably a myriad of reasons I’ve been infatuated with the Very Large Array in New Mexico.\u00a0 I finally was able to visit the VLA on my westward journey on U.S. Highway 60 from Socorro, New Mexico. Simply put, … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11,18,5],"tags":[68,67],"class_list":["post-350","post","type-post","status-publish","format-standard","hentry","category-experiences","category-photography","category-trips","tag-antennas","tag-vla"],"_links":{"self":[{"href":"https:\/\/invertedsky.net\/index.php?rest_route=\/wp\/v2\/posts\/350","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/invertedsky.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/invertedsky.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/invertedsky.net\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/invertedsky.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=350"}],"version-history":[{"count":8,"href":"https:\/\/invertedsky.net\/index.php?rest_route=\/wp\/v2\/posts\/350\/revisions"}],"predecessor-version":[{"id":370,"href":"https:\/\/invertedsky.net\/index.php?rest_route=\/wp\/v2\/posts\/350\/revisions\/370"}],"wp:attachment":[{"href":"https:\/\/invertedsky.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=350"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/invertedsky.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=350"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/invertedsky.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=350"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}