The current war between Russia and Ukraine features a lot more artillery use because both sides are reluctant or unable to employ air power. Ukraine does not have a large and effective air force and what it does have is vulnerable to ground fire from missiles as well as heavy machine-guns. Ukraine does not possess much in the way of SEAD\DEAD (Suppression of Enemy Air Defenses\Destruction of Enemy Air Defenses) aircraft or pilots experienced enough to make such aircraft work. Russia refuses to use its warplanes because, officially, there are no Russian forces inside Ukraine. This is not true but it is easier to hide ground forces (take identifying insignia off uniforms and paint over identifying insignia on vehicles) than warplanes. Hiding combat aircraft is seen as a deception too far and Russia has given up on using its warplanes in Ukrainian air space. Moreover no one will believe that the Russian backed rebels were able to create an air force from the few Ukrainian Air Force aircraft captured on the ground. Most of these were either not flyable or were bombed on the ground by the Ukrainian Air Force before they could be put into a usable state.
Artillery does not suffer from any of these issues, making it the main source of long range firepower for both sides. On top of that the military expertise, training and tactics of both sides are still heavily rooted in Soviet doctrine, which includes widespread use of artillery.
So far the heaviest systems used has been the Tochka-U (also known as SS-21) and Luna-M (an unguided rocket also known as FROG-7). Both systems are transported on truck based Transporter Erector Launchers. These missiles have ranges of 120 and 70 kilometers respectively, using explosive warheads of 480 and 390 kilograms respectively. A notable example of use of these missiles happened on February 8th, when a Ukrainian one hit a rebel artillery munitions depot west of Donetsk resulting in a spectacular secondary explosion.
The next heaviest system is the BM-30 heavy multiple rocket launcher. The 300 mm caliber rocket, weighting close to 800 kg each, carry 250 kg warheads, and have a range of up to 90 kilometers. This system is also a point of some political discussion, as so far none of it has been captured from Ukrainian Army by the rebels, yet these 300mm rockets have been fired at Ukrainian troops regularly anyway. This eventually turned into an odd indirect admission by Russia during negotiations for the February 2015 Minsk-2 ceasefire in which Russian negotiators admitted the use of these 300mm rockets by the “rebels” (actually Russian troops operating the Tornado-S system that also uses these 300mm rockets).
Tornado-S is a modernized equivalent of BM-30, which in addition to using with the same 300mm rockets as the BM-30 also has more advanced electronics, a newer truck chassis, and is lighter thanks to carrying just 6 launch tubes. Tornado-S began production in 2012 and only a few are in service with Russian forces. None have yet been exported so the rebels could not have possibly captured it from the Ukrainians.
BM-30s slightly lighter and older cousin, the BM-27 has sixteen 220mm tubes. Range of the 220mm rockets is 35 kilometers and warheads weigh between 90 and 100 kilograms while the complete rockets weight 280 kilograms. Both sides use the BM-27, as the rebels captured a small number of the vehicles.
However the the most commonly used rocket artillery system has been the 1960's era BM-21. The most common, truck mounted setup contains 40 122mm launch tubes, capable of firing an extreme variety of rockets. Thanks to its availability all over the world, various countries have developed their own rockets for the BM-21, which vary in weight from 55 to 75 kilograms, with 6 to 25 kilogram warheads, and maximum ranges between 12 and 45 kilometers. It's used by both sides in large quantities, though the separatists are also rumored to have the modernized, produced only in Russia Tornado-G, which similarly to Tornado-S and a more modern launcher for BM-21 rockets on a new chassis.
TOS-1 Buratino is an odd artillery system rumored to be very recently supplied to the separatists by Russia. Mounted on a T-72 tank chassis, it uses 24 220mm rockets with powerful thermobaric warheads, though with just few kilometer ranges, varying with model.
The extensive use of rocket artillery has been in addition to lots of tube artillery. The biggest gun on the Ukrainian battlefield is the 2S7 203mm (8 inch) self-propelled gun based on a T-80 tank chassis. Recently reactivated from deep storage, these vehicles can lob shells weighting up to 100 kilograms to as far as 55 kilometers with rocket assisted projectiles. Ukraine as well as the rebels are using lighter Self Propelled Guns though, like the 152mm 2S5, 152mm 2S19, 122mm 2S3a, 122mm 2S1 and the 120mm mortar 2S9. Towed tube artillery is also used by both sides, used models including 152mm 2A65 and the old 152mm D20 and 122mm D-30 howitzers.
Satellite and aerial photos not only show Russian artillery and rocket launchers entering Ukraine but also being used there. Photos also show Russian artillery and rocket launchers just across the border in Russia firing into Ukraine. --Adam Szczepanik