Skip to content
View in the app

A better way to browse. Learn more.

Thailand News and Discussion Forum | ASEANNOW

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

Mysterious "missile" launch seen off Los Angeles coast a "problem of perspective"

Featured Replies

Mysterious "missile" launch seen off Los Angeles coast a "problem of perspective"

2010-11-10 01:27:45 GMT+7 (ICT)

LOS ANGELES (BNO NEWS) -- A suspected missile launch was seen on Monday afternoon over California's southwestern Pacific coast, and after government officials have remained uncertain about its origin, a group of scientists on Tuesday explained that it is a simple a problem of perspective.

A KCBS-TV news helicopter in Los Angeles captured the large "missile" at around 5 p.m. local time. According to the crew, the location of the missile was about 35 miles into the sea, west of Los Angeles and north of Catalina Island.

While a Navy spokesperson said no activity was reported during that time, California's Vandenberg Air Force Base said no launches had been conducted since Friday's Delta II rocket, which carried an Italian satellite into orbit.

A spokesperson from the Pentagon later said they were still trying to resolve what the contrail was caused by, but that it was not activity from the Department of Defense as they held talks with the Air Force, Navy and the North American Aerospace Defense Command.

However, it seems perspective played a trick on the viewers' eyes, and the contrail was probably formed by an airplane.

According to contrailscience.com, the idea that it is a missile launch originates from three misconceptions: "firstly that the trail is vertical – it's not, it's a horizontal trail, at around 32,000 feet (about six miles); secondly, the misconception of direction, that it's flying away from the viewer, when it's actually flying towards the viewer; and thirdly, the idea that it goes all the way down to the ground."

Just as we view completely "straight" roads while driving, in reality, it is just the angle we view it from. A snapshot of the roads from an airplane would reveal that they are not straight lines. The contrail is no more vertical than the road is, the website states.

While the "base" of the contrail seems wider than the tip, which tells the brain that this means the base is closer and the object is flying away, in reality, it has simply been spread by the wind.

"Imagine if a plane with a 100 mile long spreading contrail were coming towards you; what would it look like? It would look exactly like this," contrailscience.com explains.

The third misconception creates the illusion that the base goes all the way down to the ground, which would be true if the Earth were flat, contrailscience.com notes. "But the Earth is round, and things go beneath the horizon eventually, no matter how high they are. A plane 200 miles away but five miles up is always below the horizon. If the horizon is raised (as it is here, with Catalina Island), then the distance is less."

According to Ross Marsden, from New Zealand's Metservice, in order for contrails to form, the ambient air temperature needs to be lower than a certain temperature, which mostly depends on the altitude and the relative humidity.

In addition, it depends on the jet engine type and engine efficiency. Usually contrails dissipate a few plane-lengths behind the aircraft, but if the air is moist enough to be ice-saturated they will remain in the sky and behave like any other cirrus cloud. Persistent contrails eventually dissipate or merge with other cirrus, Marsden explains.

Reports of the supposed "missile" all came from the same area, the coast of San Clemente, Orange County, California. People in other areas, such as Los Angeles, would have simply seen a contrail not worth mentioning because of perspective.

tvn.png

-- © BNO News All rights reserved 2010-11-10

Create an account or sign in to comment

Recently Browsing 0

  • No registered users viewing this page.

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.