Under $200

Ultra-diffuse galaxies are generally quenched dwarf galaxies with no gas reservoirs, they are therefore unable to form new stars; as a result, ...

Features Flashlight mode has a low beam option that illuminates up to 40 meters and a high beam option that reaches up to 100 meters Floodlight m...

The universe has always been mysterious and strange to us, but in fact it may be stranger than we can ever fathom. In this episode of How Do You...

Features Detect coins, jewelry and other metal objects up to 6 inches below the surface LCD display and audio tones alert searchers to presence ...

Features Dark-Sky filter Contrast increase in aurora & deep-sky photography Reduction of stray light from street lights, for example Wide-ang...

In the second part of Dr. Barth's discussion on dark matter, he touches on why did galaxies form, the missing matter problem, and the Great Attr...

In this episode, Dr. Barth discusses the the difference between persuading someone to accept your opinion in an argument and arguing from eviden...

Features High quality Explore Scientific O-III filter Let only the oxygen emission lines "through" Absorbs all other emission lines Absorbs almo...

Features High quality Explore Scientific S-II filter Absorbs all other emission lines Absorbs almost all of the artificial light Passband bandwid...

Features High quality Explore Scientific S-II filter Absorbs all other emission lines Absorbs almost all of the artificial light Passband bandwid...

Features High quality Explore Scientific H-Alpha filter Lets only the emission lines of hydrogen "through" Absorbs almost all of the artificial l...

Features High quality Explore Scientific H-Alpha filter Lets only the emission lines of hydrogen "through" Absorbs almost all of the artificial l...

Features High quality Explore Scientific H-Alpha filter Lets only the emission lines of hydrogen "through" Absorbs almost all of the artificial l...

The creation of Earth's Moon is an age old question. There are pre-Apollo mission theories, of which three of the most popular ones will be d...

Get the National Geographic Carbon Trekking Poles Set for FREE, when purchasing 10x42 Waterproof Performance Roof Binoculars. To activate this pro...

It's estimated that we will colonize Mars by 2050. The challenges to make it happen are daunting.  Dr. Barth touches on some of the problems tha...

Features 4K HD Camera Waterproof Case Flat Adhesive Mounts Handle Bar/Pole Mount Frame Housing Mount Straps Long Thumb Screw Quick Release Buckle...

Dr. Daniel Barth returns with the 33rd episode of 'How Do You KNOW?' to discuss the Three Ring Theory that explains the formation of our solar s...

Features Combination of fully multi-coated lenses and superior Bak-4 prisms creates images with excellent contrast and clarity 42mm aperture has ...

Features Combination of fully multi-coated lenses and superior Bak-4 prisms creates images with excellent contrast and clarity 42mm aperture has ...

Features Combination of fully multi-coated lenses and superior Bak-4 prisms generate images rich in contrast Combination of fully multi-coated le...

Features Compact size keeps the binocular lightweight for grab-and-go adventures and extended observing 8x magnification provides excellent detai...

Features Compact size keeps the binocular lightweight for grab-and-go adventures and extended observing Combination of fully multi-coated lenses ...

Dr. Daniel Barth gives us an overview of and will answer your questions about the James Webb Space Telescope in this 34th Episode of How Do You ...

Dr. Daniel Barth gives us an overview of and will answer your questions about Lagrange Points in this 35th Episode of How Do You KNOW? https://e...

Dr. Daniel Barth gives us an overview of and will answer your questions about what happens When Asteroids Strike in this 36th Episode of How Do ...

What happens when the sun releases energy to create prominences, flares, mass ejections, and tsunamis, and how can those events affect us on ...

Description Using this accessory plate, you can use telescope and camera side by side By sliding this accessory plate into your standard Vixen Do...

Description Finder Bracket to facilitate Optical axis adjustment Short bracket for Vixen Finder Scope. Use with item #2654, finder bracket shoe, ...

Description Converts 60mm thread to 53mm thread Available for FL and ED OTAs. Specs Optical Path Length 4mm Weight 22g Warranty Vix...

Description Converts 53mm thread to 43mm thread Available for FL and ED OTAs. Specs Optical Path Length 3mm Weight 19g Warranty Vix...

Description For stable astrophotography Stable astrophotography can be available. Vixen's Weight Shaft Camera Bracket allows for the attachment ...

Description For Prime Focus Photography with Telescope Leaves the inner diameter large by attaching a T Ring by screwing in each of the knobs, i...

On this episode of How Do You KNOW? Dr Daniel Barth will be discussing what all is involved in the Fine Tuning of Nature.  Because we tend to suspe...

Features 3x Magnification Carry Case Included Lanyard Description Be ready whenever adventure calls with the lightweight National Geographi...

Description For smooth setting up of POLARIE and AP equatorial mount The polar meter is a "unlikely" design that summarizes level, compass and in...

Description It allows you to use an polar alignment scope PF-LII, polar alignment scope PF-L or SX polar axis scope for the POLARIE U. The polar s...

Features Very high sharpness and contrast across the entire field of view Almost no color defects due to lanthanum glass Twist-Up eyecup for peop...

Features Very high sharpness and contrast across the entire field of view Almost no color defects due to lanthanum glass Twist-Up eyecup for peop...

Description Connects Telescope, Spotting Scope with DSLR Camera The T Ring is designed to be used for Astrophotography in conjunction with other ...

Description Connects Telescope, Spotting Scope with DSLR Camera The T Ring is designed to be used for Astrophotography in conjunction with other ...