Astronomy laser pointers are very useful tools for backyard stargazing. Due to miniaturization and affordable technology, green laser pointers are now cheaply available for every amateur astronomer.

I love using them for pointing at faint objects in the night sky, especially when I’m trying to show someone else what I’m looking at. It gets rid of all those “No, not that star, I’m talking about THAT one!” conversations.

But, as useful as laser pointers are for astronomy, they can land you in serious trouble if you’re not careful with them and stick to the rules of using them.

In this article, I’ll share everything you need to know for their safe and fun use.

Best Astronomy Laser Pointers

There are dozens of laser pointers for astronomy on the market. A simple search of Amazon will bring up dozens for you to choose from.

The one I’ve used for years is no longer on the market, but I’ve had a look through some options and these three models have great reviews and cover a variety of price points.

If you’re interested in any of them, use the underlined link in the table to open a new tab. I’ll earn a small affiliate commission if you purchase one using a link but it won’t affect the price that you pay.

Laser Pointer

Price

Our Rating

Ideal For…

Check on Amazon
Olight Arkfeld Flat$$$5/5 

Premium use + flashlight

Today’s Price
Basic Green Laser$4.5/5 

Simplicity

Today’s Price
Eazmong Ultra Bright

$$

4/5 

High Specification

Today’s Price
Click on the underlined links in the table to check prices and customer reviews on Amazon

Laser Pointer Basics

Lasers are used by many backyard astronomers and are commonly referred to as either pointers or astronomy laser pens because of their pen-like shape and dimensions.

A laser pen’s small, round shape is ideal for backyard astronomers because it fits in the finderscope holder on your telescope tube. This makes such lasers ideal to use both as a pointer and a convenient finderscope.

Example laser pointer holder for a telescope (buy here)

When aligned with your telescope, a laser pointer used alongside a traditional finderscope produces great results. Even before looking through the finderscope, the green laser light shows you exactly where the telescope is pointing.

In a moment, I’ll share another neat trick you can do with an astronomy pen laser that shows you exactly where your telescope is pointing.

Why are Astronomy Lasers Green?

Lasers come in all sorts of colors, but, the ones used for our purpose are green or, more rarely, blue. This is because the human eye is most sensitive to colors from the green-yellow spectrum, so following them up in the night sky is a breeze.

Additionally, green lasers are brighter than red and blue for any given amount of power. This makes them ideal as small, powerful, handheld instruments running on a battery.

Laser Power and Brightness

The brightness of a laser is determined by its power output. The higher the power, the brighter the laser. However, this is only true for a fixed wavelength (color).

For instance, a green and red laser at the same power output will not have equal brightness. In this example, the green laser will be brighter.

Also, keep in mind that when it comes to power output, higher is not always better. Don’t be tempted to buy a high-powered laser: you won’t need it for backyard astronomy purposes.

And that’s a good thing!

For one, high-powered lasers are more expensive. Secondly, a high-power laser will cause your eyes to refocus every time you use it. This causes unnecessary discomfort and risks upsetting your night vision.

The key is to buy a laser pointer bright enough for the laser beam to be clearly seen but not so bright that your vision suffers.

To help you decide, here’s a chart showing how much power you’ll need under different conditions:

Laser Color

Personal Use

Public Use

Green

5 mW – 30 mW

15 mW – 100 mW

Blue

5 mW – 50 mW

50 mW – 150 mW

Red

50 mW – 100 mW

100 mW – 300 mW

How to Use an Astronomy Laser Pointer

Now that you know the basics, it’s time to start using your green laser pointer for astronomy!

Let’s explore the two main ways we can use a laser pointer for stargazing.​

Using Lasers to Highlight Stellar Objects

The most obvious use of laser pointers is, well, pointing at night sky objects!

You can show your friends around the night sky much more accurately with lasers, especially when you are addressing a group of people, than you can by using your fingers and verbal descriptions.

Laser pointer at night
Laser pointer in use (source)

When you want to point out an object to a friend or fellow member of your astronomy club, make sure no aircraft can be seen or heard nearby. Only when you’re sure the sky is clear, press your laser on and point the beam exactly where the object can be found.

Please only use a laser pointer that needs a button to be pressed for it to work, i.e. avoid the ‘always on’ variety.​

As soon as the person can see where you are pointing, turn the laser off again.​

Remember that other neat trick I mentioned earlier?

Well, point your laser down the eyepiece of your telescope and watch as it shoots out the optical tube into the sky to show exactly where your telescope is pointing!

Using Lasers as a Second Finderscope

Laser pointers make a great second finderscope, and it’s a more practical way of using them than firing them down your telescope’s eyepiece.

You’ll need a second mount alongside your traditional finderscope to make it work (like the one in the picture above), and some astronomers love to work this way.

Green laser pointer in place of finderscope on telescope
Green laser pointer as a finderscope (source)

In combination, these two tools can work wonders for increasing the speed and accuracy with which you get the telescope objective on point!

The main benefit of using a laser as a finderscope is that you don’t need to bend over and look through them every time you hunt an object down. Instead, just follow the beam as you casually move your telescope to the correct part of the sky, only using the traditional finderscope for the final adjustment.

Laser Pointer Laws and Guidance on Use 

A laser is a highly focused beam of light. It can travel a long distance without diverging too much. This makes it useful for pointing out stars on a dark night… and also potentially dangerous to people in the air.

There have been many cases of people pointing lasers into planes and helicopters, only to land themselves in trouble.

What you may not realize is that your point-sized laser beam can fill an entire cockpit with a stinging green light.

For example, at a distance of 500 ft, what looks like a laser dot can be a circle of high-intensity light about 6 ft wide.

Such a laser can temporarily blind the pilot and the crew, putting their lives in danger and those of all their passengers. It’s equivalent to a camera flash in your eyes whilst driving a car on a pitch-black night, so you can understand why the rules on using laser pointers are strict.

This quote highlights the legal penalty and the incidents of lasering aircraft:

“Interfering with the operation of an aircraft is a crime punishable by a maximum of 20 years in prison and a $250,000 fine.

In 2009, there were 1,489 laser events logged with the FAA—that is, pilots reporting that their cockpits were illuminated by the devices. The following year, that figure had nearly doubled to 2,836.”

The latest FAA data for 2023 shows there were 13,304 incidents, which is over 35 per day.

Astronomy Laser Safety Advice

These rules on safe outdoor laser use are simple and pretty obvious. Nevertheless, they’re worth stating here and for all of us to pay attention to:

  • Never shine a laser pointer toward any person, aircraft, or other vehicle.
  • Never look directly into the beam of any laser pointer
  • Do not allow children to use them unsupervised
  • Don’t aim a laser skyward if you can see or hear any type of aircraft overhead
  • Don’t use laser pointers within 2 miles (3 kilometers) of an airport
  • Pointers must have a ‘caution’ or ‘danger’ sticker on them. Don’t buy without.
Danger sticker on laser pointer
Danger sticker on a laser

Buying an Astronomy Laser Pen

Having read the precautions, here are a few things to keep in mind when buying a laser.

As a backyard astronomer, all you need is a medium-sized green laser pointer. Laser pointers especially developed for astronomy are easy to find, and I’ve recommended three in the table below.

One final aspect that most people overlook when they buy a laser is its operating temperature.

If you live in a cold place where snow is common, you may find that the laser malfunctions in the chill of the night. Most common laser pointers malfunction when the internal temperature drops below freezing, so keep them out of the cold, or get one that’s cold and frost-resistant. These are expensive but can be used well below freezing point.

Our Best Green Laser Pointers for Astronomy

Laser Pointer

Price

Our Rating

Ideal For…

Check on Amazon
Olight Arkfeld Flat$$$5/5 

Premium use + flashlight

Today’s Price
Basic Green Laser$4.5/5 

Simplicity

Today’s Price
Eazmong Ultra Bright

$$

4/5 

High Specification

Today’s Price
Click on the underlined links in the table to check prices and customer reviews on Amazon

Summing Up

Green laser pointers are a cheap, portable and effective piece of astronomy equipment.

You have to use them safely and they’re not to everyone’s taste, but if you are involved in outreach or regularly view the night sky with fellow astronomers, you’ll not regret having one in your collection.

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